CVE-2026-120252
CVE-2026-120252
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.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Weakness classification (CWE)
References
- github.com/cgohlke/imagecodecs/issues/157 (issue-tracking)
- github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/jpegsof3/jpegsof3.cpp (technical-description)
- github.com/cgohlke/imagecodecs (product)
- www.vulncheck.com/advisories/imagecodecs-2023.1.23-through-2026.10.10-stack-buf… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-120252?
- CVE-2026-120252 is a medium-severity vulnerability, classified under Stack-based Buffer Overflow. CVSS score: 5.5/10. Published 2026-11-01.
- How severe is CVE-2026-120252?
- Medium severity. CVSS v3 base score is 5.5 out of 10.