CVE-2026-31971 (GCVE-0-2026-31971)
Vulnerability from cvelistv5 – Published: 2026-03-18 19:55 – Updated: 2026-03-18 20:15
VLAI?
Title
HTSlib CRAM decoder vulnerable to buffer overflow
Summary
HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data using a variety of encodings and compression methods. When reading data encoded using the `BYTE_ARRAY_LEN` method, the `cram_byte_array_len_decode()` failed to validate that the amount of data being unpacked matched the size of the output buffer where it was to be stored. Depending on the data series being read, this could result either in a heap or a stack overflow with attacker-controlled bytes. Depending on the data stream this could result either in a heap buffer overflow or a stack overflow. If a user opens a file crafted to exploit this issue it could lead to the program crashing, overwriting of data structures on the heap or stack in ways not expected by the program, or changing the control flow of the program. It may be possible to use this to obtain arbitrary code execution. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.
Severity ?
CWE
Assigner
References
| URL | Tags | |||||||
|---|---|---|---|---|---|---|---|---|
|
||||||||
Impacted products
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-31971",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-18T20:15:12.038273Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-18T20:15:22.414Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "htslib",
"vendor": "samtools",
"versions": [
{
"status": "affected",
"version": "\u003c 1.21.1"
},
{
"status": "affected",
"version": "\u003e= 1.22, \u003c 1.22.2"
},
{
"status": "affected",
"version": "= 1.23"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data using a variety of encodings and compression methods. When reading data encoded using the `BYTE_ARRAY_LEN` method, the `cram_byte_array_len_decode()` failed to validate that the amount of data being unpacked matched the size of the output buffer where it was to be stored. Depending on the data series being read, this could result either in a heap or a stack overflow with attacker-controlled bytes. Depending on the data stream this could result either in a heap buffer overflow or a stack overflow. If a user opens a file crafted to exploit this issue it could lead to the program crashing, overwriting of data structures on the heap or stack in ways not expected by the program, or changing the control flow of the program. It may be possible to use this to obtain arbitrary code execution. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "PASSIVE",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-121",
"description": "CWE-121: Stack-based Buffer Overflow",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-122",
"description": "CWE-122: Heap-based Buffer Overflow",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787: Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-1284",
"description": "CWE-1284: Improper Validation of Specified Quantity in Input",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-18T19:55:20.379Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/samtools/htslib/security/advisories/GHSA-jvx4-4wq7-6fmh",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/samtools/htslib/security/advisories/GHSA-jvx4-4wq7-6fmh"
},
{
"name": "https://github.com/samtools/htslib/commit/01cd003b46fa2ebea4d9be5475b11217eb4c11be",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/samtools/htslib/commit/01cd003b46fa2ebea4d9be5475b11217eb4c11be"
}
],
"source": {
"advisory": "GHSA-jvx4-4wq7-6fmh",
"discovery": "UNKNOWN"
},
"title": "HTSlib CRAM decoder vulnerable to buffer overflow"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-31971",
"datePublished": "2026-03-18T19:55:20.379Z",
"dateReserved": "2026-03-10T15:40:10.486Z",
"dateUpdated": "2026-03-18T20:15:22.414Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-31971",
"date": "2026-04-14",
"epss": "0.0013",
"percentile": "0.32466"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-31971\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-03-18T20:16:22.243\",\"lastModified\":\"2026-03-19T13:58:31.573\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data using a variety of encodings and compression methods. When reading data encoded using the `BYTE_ARRAY_LEN` method, the `cram_byte_array_len_decode()` failed to validate that the amount of data being unpacked matched the size of the output buffer where it was to be stored. Depending on the data series being read, this could result either in a heap or a stack overflow with attacker-controlled bytes. Depending on the data stream this could result either in a heap buffer overflow or a stack overflow. If a user opens a file crafted to exploit this issue it could lead to the program crashing, overwriting of data structures on the heap or stack in ways not expected by the program, or changing the control flow of the program. It may be possible to use this to obtain arbitrary code execution. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"LOW\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H\",\"baseScore\":8.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.2}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-121\"},{\"lang\":\"en\",\"value\":\"CWE-122\"},{\"lang\":\"en\",\"value\":\"CWE-787\"},{\"lang\":\"en\",\"value\":\"CWE-1284\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:htslib:htslib:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.21.1\",\"matchCriteriaId\":\"A069D6B6-FFF6-4DB7-9811-A568ECC4B288\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:htslib:htslib:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.22\",\"versionEndExcluding\":\"1.22.2\",\"matchCriteriaId\":\"D9D525C8-C8AD-4368-A396-EB4D9DA02B1C\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:htslib:htslib:1.23:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"AAA6BBB2-76F3-4372-9BAE-FDE157401EFD\"}]}]}],\"references\":[{\"url\":\"https://github.com/samtools/htslib/commit/01cd003b46fa2ebea4d9be5475b11217eb4c11be\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\"]},{\"url\":\"https://github.com/samtools/htslib/security/advisories/GHSA-jvx4-4wq7-6fmh\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Vendor Advisory\"]}]}}",
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-31971\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-18T20:15:12.038273Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-18T20:15:14.940Z\"}}], \"cna\": {\"title\": \"HTSlib CRAM decoder vulnerable to buffer overflow\", \"source\": {\"advisory\": \"GHSA-jvx4-4wq7-6fmh\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 7.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N\", \"userInteraction\": \"PASSIVE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"LOW\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"samtools\", \"product\": \"htslib\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.21.1\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.22, \u003c 1.22.2\"}, {\"status\": \"affected\", \"version\": \"= 1.23\"}]}], \"references\": [{\"url\": \"https://github.com/samtools/htslib/security/advisories/GHSA-jvx4-4wq7-6fmh\", \"name\": \"https://github.com/samtools/htslib/security/advisories/GHSA-jvx4-4wq7-6fmh\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/samtools/htslib/commit/01cd003b46fa2ebea4d9be5475b11217eb4c11be\", \"name\": \"https://github.com/samtools/htslib/commit/01cd003b46fa2ebea4d9be5475b11217eb4c11be\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data using a variety of encodings and compression methods. When reading data encoded using the `BYTE_ARRAY_LEN` method, the `cram_byte_array_len_decode()` failed to validate that the amount of data being unpacked matched the size of the output buffer where it was to be stored. Depending on the data series being read, this could result either in a heap or a stack overflow with attacker-controlled bytes. Depending on the data stream this could result either in a heap buffer overflow or a stack overflow. If a user opens a file crafted to exploit this issue it could lead to the program crashing, overwriting of data structures on the heap or stack in ways not expected by the program, or changing the control flow of the program. It may be possible to use this to obtain arbitrary code execution. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-121\", \"description\": \"CWE-121: Stack-based Buffer Overflow\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-122\", \"description\": \"CWE-122: Heap-based Buffer Overflow\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-787\", \"description\": \"CWE-787: Out-of-bounds Write\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-1284\", \"description\": \"CWE-1284: Improper Validation of Specified Quantity in Input\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-03-18T19:55:20.379Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-31971\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-18T20:15:22.414Z\", \"dateReserved\": \"2026-03-10T15:40:10.486Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-03-18T19:55:20.379Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
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.
Loading…
Loading…