Auth bypass in Xiph Theora
CVE-2024-56431
oc_huff_tree_unpack in huffdec.c in libtheora in Theora through 1.0 7180717 has an invalid negative left shift. NOTE: this is disputed by third parties because there is no evidence of a security impact, e.g., an application would not crash.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.019 (78.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/xiph/theora/issues/17 (Issue Tracking)
- github.com/xiph/theora/blob/7180717276af1ebc7da15c83162d6c5d6203aabf/lib/huffde… (Product)
- github.com/UnionTech-Software/libtheora-CVE-2024-56431-PoC (Exploit)
- www.openwall.com/lists/oss-security/2025/04/25/6
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2024-56431?
- CVE-2024-56431 is a critical-severity vulnerability in Xiph Theora, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2024-12-25.
- How severe is CVE-2024-56431?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2024-56431 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.