Vulnerability · Published Oct 15, 2026 · Assigned by VulnCheck
CVE-2026-111273unarr through 1.1.1 Off-by-One Heap Buffer Overflow via tar_get_name
Medium 6.1
In plain English
A medium-severity security flaw in unarr from selmf. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).
Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.2%top 88.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | unarr | no fix listed | DEBIAN-CVE-2026-111273 |
| Ubuntu:22.04:LTS | unarr | no fix listed | UBUNTU-CVE-2026-111273 |
| Ubuntu:24.04:LTS | unarr | no fix listed | UBUNTU-CVE-2026-111273 |
Affected products (as reported)
Weakness: CWE-193 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
References
- https://hackmd.io/@haind-pwn/unarr-tar-zip-oob technical-description
- https://github.com/selmf/unarr/blob/b211040df83dee513362cdeb9bd87afa26fd5e38/tar/parse-tar.c#L242-L254 technical-description
- https://github.com/selmf/unarr product
- VulnCheck Advisory: unarr through 1.1.1 Off-by-One Heap Buffer Overflow via tar_get_name third-party-advisory
- https://hackmd.io/@haind-pwn/cve-2026-111273-111274-unarr-tar-zip-oob exploit