Vulnerability · Published Nov 4, 2026 · Assigned by VulnCheck
CVE-2026-121942ZBar through 0.23.95 Out-of-Bounds Read via _zbar_sq_decode() in sqcode.c
Medium 6.1
In plain English
A medium-severity out-of-bounds read in zbar from mchehab. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities).
Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.2%top 84.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
ZBar through 0.23.95 contains an out-of-bounds read vulnerability in _zbar_sq_decode() in zbar/sqcode.c that allows attackers to read heap memory outside the image buffer via crafted SQ code images. Attackers can supply an image with a skewed SQ code finder pattern near the edge, producing unchecked sample coordinates that crash the decoder and leak bytes into output.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | zbar | no fix listed | DEBIAN-CVE-2026-121942 |
| Debian:13 | zbar | no fix listed | DEBIAN-CVE-2026-121942 |
| Debian:14 | zbar | no fix listed | DEBIAN-CVE-2026-121942 |
| Ubuntu:24.04:LTS | zbar | no fix listed | UBUNTU-CVE-2026-121942 |
| Ubuntu:26.04:LTS | zbar | no fix listed | UBUNTU-CVE-2026-121942 |
| Ubuntu:26.10 | zbar | no fix listed | UBUNTU-CVE-2026-121942 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
References
- https://github.com/mchehab/zbar/issues/351 issue-tracking
- https://hackmd.io/@haindpwn/zbar-sqcode-sampling-oob-read third-party-advisory
- https://github.com/mchehab/zbar/blob/0.23.95/zbar/sqcode.c#L529-L567 technical-description
- VulnCheck Advisory: ZBar through 0.23.95 Out-of-Bounds Read via _zbar_sq_decode() in sqcode.c third-party-advisory
- https://hackmd.io/@haindpwn/cve-2026-121942-zbar-sqcode-sampling-oob-read exploit