Buffer overflow in Strukturag Libheif
CVE-2026-3950
A vulnerability was identified in strukturag libheif up to 1.21.2. This impacts the function Track::load of the file libheif/sequences/track.cc of the component stsz/stts. The manipulation leads to out-of-bounds read. The attack needs to be performed locally. The exploit is publicly available and might be used. Applying a patch is the recommended action to fix this issue. The patch available is inofficial and not approved yet.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.002 (4.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Strukturag Libheif — versions 1.21.0, 1.21.1, 1.21.2
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, vdb-entry)
- vuldb.com/ (signature, permissions-required)
- vuldb.com/ (third-party-advisory)
- github.com/strukturag/libheif/issues/1715 (issue-tracking)
- github.com/Niebelungen-D/pocs/tree/main/heif_dec_sequence_chunk_idx_oob (exploit)
- github.com/strukturag/libheif/pull/1721 (issue-tracking, patch)
- github.com/strukturag/libheif/ (product)
Frequently asked questions
- What is CVE-2026-3950?
- CVE-2026-3950 is a low-severity vulnerability in Strukturag Libheif, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 3.3/10. Published 2026-03-11.
- How severe is CVE-2026-3950?
- Low severity. CVSS v3 base score is 3.3 out of 10.