CVE-2026-111273: Off-by-one Error in selmf unarr
Description
An off-by-one heap-based buffer overflow vulnerability exists in unarr through version 1.1.1 in the tar_get_name() function, reachable via the ar_entry_get_name() API. This flaw allows an attacker to supply a crafted TAR archive with a full ustar prefix and name, causing a NUL byte to be written past the allocated buffer, leading to heap memory corruption and potential process crash.
CVSS v4.0
Score 6.9medium
Affected software
selmf
unarr
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-111273 is an off-by-one heap-based buffer overflow vulnerability in the unarr library (versions up to 1.1.1). The issue occurs in the tar_get_name() function within tar/parse-tar.c, which is accessible through the ar_entry_get_name() API. When processing a specially crafted TAR archive containing a full ustar prefix and name, the code writes a NUL byte one byte beyond the allocated buffer, corrupting heap memory and potentially crashing the process.
Potential Impact
The vulnerability can cause heap memory corruption and process crashes when unarr processes maliciously crafted TAR archives. There is no indication of privilege escalation or remote code execution from the provided data. The CVSS 4.0 score of 6.9 reflects a medium severity with local attack vector, low attack complexity, no privileges required, and user interaction needed.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is provided in the available data. Until a patch is available, avoid processing untrusted TAR archives with unarr versions up to 1.1.1.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-15T19:33:20.652Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad14e2f2cdf04f6566084f4
Added to database: 10/15/2026, 22:05:35 UTC
Last enriched: 10/15/2026, 22:34:11 UTC
Last updated: 10/15/2026, 22:34:11 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.