Use After Free in Fraunhoferhhi Vvdec
CVE-2026-124307
Fraunhofer HHI VVdeC before 3.2.1 contains a heap use-after-free vulnerability that allows attackers to corrupt memory by redefining an ALF adaptation parameter set id still referenced by slices. Attackers can supply a crafted VVC bitstream that, with multithreaded decoding, makes worker threads dereference freed APS objects in CABACReader::readAlf() and AdaptiveLoopFilter::reconstructCoeff(), causing crashes or heap corruption.
Vulnerability class: Use-After-Free
Published .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/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.
Affected products
Weakness classification (CWE)
References
- github.com/fraunhoferhhi/vvdec (product)
- github.com/fraunhoferhhi/vvdec/blob/v3.2.0/source/Lib/CommonLib/ParameterSetMan… (technical-description)
- github.com/fraunhoferhhi/vvdec/blob/v3.2.0/source/Lib/CommonLib/Slice.h (technical-description)
- github.com/fraunhoferhhi/vvdec/blob/v3.2.0/source/Lib/DecoderLib/CABACReader.cpp (technical-description)
- github.com/fraunhoferhhi/vvdec/commit/1eddb30c4b8e02f3d13ba24aa7e52f1aa7b08c01 (patch)
- github.com/fraunhoferhhi/vvdec/issues/390 (issue-tracking)
- github.com/fraunhoferhhi/vvdec/issues/391 (issue-tracking)
- VulnCheck Advisory: Fraunhofer HHI VVdeC before 3.2.1 Heap Use-After-Free via ALF APS Redefinition (third-party-advisory)
Frequently asked questions
- What is CVE-2026-124307?
- CVE-2026-124307 is a medium-severity vulnerability in Fraunhoferhhi Vvdec, classified under Use After Free. CVSS score: 5.8/10. Published 2026-11-07.
- How severe is CVE-2026-124307?
- Medium severity. CVSS v3 base score is 5.8 out of 10.