Vulnerability · Published Nov 1, 2026 · Assigned by VulnCheck
CVE-2026-120252imagecodecs 2023.1.23 through 2026.10.10 Stack Buffer Overflow via jpegsof3_decode()
Medium 5.5
In plain English
A medium-severity stack buffer overflow in imagecodecs from cgohlke. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.1%top 96.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
imagecodecs 2023.1.23 through 2026.10.10 contains a stack-based buffer overflow vulnerability in the lossless JPEG Define Huffman Table parser in decode_jpegsof3(). Attackers can supply a crafted lossless JPEG whose DHT symbol counts wrap an 8-bit sum, overflowing the 32-entry HufVal and HufSz stack arrays and crashing the calling process.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| cgohlke | imagecodecs | 2023.1.23 – through 2026.10.10 |
Weakness: CWE-121 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
- GitHub Issue #157 issue-tracking
- https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/jpegsof3/jpegsof3.cpp#L394 technical-description
- https://github.com/cgohlke/imagecodecs product
- VulnCheck Advisory: imagecodecs 2023.1.23 through 2026.10.10 Stack Buffer Overflow via jpegsof3_decode() third-party-advisory