CVE-2026-111273
unarr through 1.1.1 contains an off-by-one heap-based buffer overflow in tar_get_name() in tar/parse-tar.c, reachable through the ar_entry_get_name() API. Attackers can supply a crafted TAR archive with a full ustar prefix and name to write a NUL byte past the allocation, corrupting heap memory and crashing the process.
CVSS
- Base score
- 6.9
- Version
- 4.0
- Vector
- CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/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
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.14 %
- Percentile among all scored CVEs
- 3
- Score date
- 10/20/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
ATT&CK techniques
How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.
- Exploitation
T1203Exploitation for Client Executionexecution60 %
Inferred by deterministic rules from the CVSS vector and CWE. Indicative only.
ATT&CK mitigations that cover these techniques
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
CWEs
- CWE-193
References
Show 5 references
- https://github.com/selmf/unarr
- https://github.com/selmf/unarr/blob/b211040df83dee513362cdeb9bd87afa26fd5e38/tar/parse-tar.c#L242-L254
- https://hackmd.io/@haind-pwn/unarr-tar-zip-oob
- https://www.vulncheck.com/advisories/unarr-through-1.1.1-off-by-one-heap-buffer-overflow-via-tar-get-name
- https://hackmd.io/@haind-pwn/cve-2026-111273-111274-unarr-tar-zip-oob
Raw JSON (NVD)
Show
{
"id": "CVE-2026-111273",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-111273",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-16T19:38:21.654864Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 6.1,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 4.2,
"exploitabilityScore": 1.8
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 6.9,
"Automatable": "NOT_DEFINED",
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/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",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "PASSIVE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "LOW",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "disclosure@vulncheck.com",
"affectedData": [
{
"repo": "https://github.com/selmf/unarr",
"vendor": "selmf",
"product": "unarr",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "1.1.1"
}
],
"packageURL": "pkg:github/selmf/unarr",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-10-15T22:19:28.333",
"references": [
{
"url": "https://github.com/selmf/unarr",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/selmf/unarr/blob/b211040df83dee513362cdeb9bd87afa26fd5e38/tar/parse-tar.c#L242-L254",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://hackmd.io/@haind-pwn/unarr-tar-zip-oob",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://www.vulncheck.com/advisories/unarr-through-1.1.1-off-by-one-heap-buffer-overflow-via-tar-get-name",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://hackmd.io/@haind-pwn/cve-2026-111273-111274-unarr-tar-zip-oob",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"description": [
{
"lang": "en",
"value": "CWE-193"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "unarr through 1.1.1 contains an off-by-one heap-based buffer overflow in tar_get_name() in tar/parse-tar.c, reachable through the ar_entry_get_name() API. Attackers can supply a crafted TAR archive with a full ustar prefix and name to write a NUL byte past the allocation, corrupting heap memory and crashing the process."
}
],
"lastModified": "2026-10-16T20:17:19.853",
"sourceIdentifier": "disclosure@vulncheck.com"
}