CVE-2024-56431

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2024-12-25. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
60(Track)
EG Risk 60/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation2% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
77%
KEV
Not listed

Published

December 25, 2024

Last Modified

April 25, 2025

Advisory Details (6)

Auto-updated May 30, 2026
No patch confirmed yet.
generic

oss-security - Re: CVE-2024-56431: libtheora: incorrect bitwise shift in huffdec.c

http://www.openwall.com/lists/oss-security/2025/04/25/6
generic

oss-security - CVE-2024-56431: libtheora: incorrect bitwise shift in huffdec.c

http://www.openwall.com/lists/oss-security/2025/04/25/4
generic

oss-security - Re: CVE-2024-56431: libtheora: incorrect bitwise shift in huffdec.c

https://www.openwall.com/lists/oss-security/2025/04/25/6
generic

New stable release · Issue #17 · xiph/theora · GitHub

https://github.com/xiph/theora/issues/17#issuecomment-2480630603
generic

theora/lib/huffdec.c at 7180717276af1ebc7da15c83162d6c5d6203aabf · xiph/theora · GitHub

https://github.com/xiph/theora/blob/7180717276af1ebc7da15c83162d6c5d6203aabf/lib/huffdec.c#L193
generic

GitHub - UnionTech-Software/libtheora-CVE-2024-56431-PoC · GitHub

https://github.com/UnionTech-Software/libtheora-CVE-2024-56431-PoC

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 40× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-26 14:53 UTCEPSS rescore
  2. 2026-07-25 14:17 UTCEPSS rescore
  3. 2026-07-25 14:17 UTCEPSS rescore
  4. 2026-07-24 14:16 UTCEPSS rescore
  5. 2026-07-23 14:17 UTCEPSS rescore
  6. 2026-07-23 14:17 UTCEPSS rescore
  7. 2026-07-23 02:45 UTCEG score recompute
  8. 2026-07-22 14:07 UTCEPSS rescore
  9. 2026-07-21 15:23 UTCEPSS rescore
  10. 2026-07-20 17:07 UTCEPSS rescore
  11. 2026-07-19 14:30 UTCEPSS rescore
  12. 2026-07-19 14:30 UTCEPSS rescore
  13. 2026-07-19 02:28 UTCEPSS rescore
  14. 2026-07-19 02:28 UTCEPSS rescore
  15. 2026-07-18 10:03 UTCEPSS rescore
  16. 2026-07-16 17:02 UTCEPSS rescore
  17. 2026-07-15 16:57 UTCEPSS rescore
  18. 2026-07-15 01:59 UTCEPSS rescore
  19. 2026-07-15 01:59 UTCEPSS rescore
  20. 2026-07-13 22:29 UTCEPSS rescore
  21. 2026-07-13 16:07 UTCOSV refresh
  22. 2026-07-13 06:12 UTCEPSS rescore
  23. 2026-07-12 05:45 UTCEPSS rescore
  24. 2026-07-11 08:26 UTCEPSS rescore
  25. 2026-07-09 19:09 UTCEPSS rescore
Show 74 more
  1. 2026-07-09 19:09 UTCEPSS rescore
  2. 2026-07-08 15:14 UTCEPSS rescore
  3. 2026-07-07 13:45 UTCEPSS rescore
  4. 2026-07-07 13:45 UTCEPSS rescore
  5. 2026-07-06 16:26 UTCEPSS rescore
  6. 2026-07-06 16:26 UTCEPSS rescore
  7. 2026-07-06 02:22 UTCEPSS rescore
  8. 2026-07-05 02:29 UTCEPSS rescore
  9. 2026-07-04 06:30 UTCEPSS rescore
  10. 2026-07-04 06:30 UTCEPSS rescore
  11. 2026-07-01 15:06 UTCEPSS rescore
  12. 2026-06-30 23:21 UTCEPSS rescore
  13. 2026-06-30 23:21 UTCEPSS rescore
  14. 2026-06-29 14:05 UTCEPSS rescore
  15. 2026-06-28 14:07 UTCEPSS rescore
  16. 2026-06-28 04:55 UTCEPSS rescore
  17. 2026-06-28 04:55 UTCEPSS rescore
  18. 2026-06-27 03:08 UTCEPSS rescore
  19. 2026-06-27 03:07 UTCEPSS rescore
  20. 2026-06-25 13:49 UTCEPSS rescore
  21. 2026-06-25 13:49 UTCEPSS rescore
  22. 2026-06-25 13:31 UTCOSV refresh
  23. 2026-06-24 14:04 UTCEPSS rescore
  24. 2026-06-24 14:04 UTCEPSS rescore
  25. 2026-06-23 21:32 UTCEPSS rescore
  26. 2026-06-22 14:25 UTCEPSS rescore
  27. 2026-06-22 14:25 UTCEPSS rescore
  28. 2026-06-21 14:56 UTCEPSS rescore
  29. 2026-06-21 14:56 UTCEPSS rescore
  30. 2026-06-21 01:59 UTCEPSS rescore
  31. 2026-06-19 19:25 UTCEPSS rescore
  32. 2026-06-19 19:25 UTCEPSS rescore
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-18 17:52 UTCEPSS rescore
  35. 2026-06-17 17:52 UTCEPSS rescore
  36. 2026-06-16 17:52 UTCEPSS rescore
  37. 2026-06-15 17:48 UTCEPSS rescore
  38. 2026-06-13 22:59 UTCEPSS rescore
  39. 2026-06-13 22:59 UTCEPSS rescore
  40. 2026-06-12 23:11 UTCEPSS rescore
  41. 2026-06-12 23:11 UTCEPSS rescore
  42. 2026-06-11 13:59 UTCEPSS rescore
  43. 2026-06-11 13:59 UTCEPSS rescore
  44. 2026-06-10 22:18 UTCEPSS rescore
  45. 2026-06-10 22:18 UTCEPSS rescore
  46. 2026-06-10 13:21 UTCEPSS rescore
  47. 2026-06-08 03:58 UTCOSV refresh
  48. 2026-06-07 15:24 UTCEPSS rescore
  49. 2026-06-07 15:24 UTCEPSS rescore
  50. 2026-06-06 13:46 UTCEPSS rescore
  51. 2026-06-06 13:46 UTCEPSS rescore
  52. 2026-06-05 22:46 UTCEPSS rescore
  53. 2026-06-05 22:46 UTCEPSS rescore
  54. 2026-06-05 06:09 UTCEPSS rescore
  55. 2026-06-05 06:09 UTCEPSS rescore
  56. 2026-06-04 13:11 UTCEPSS rescore
  57. 2026-06-04 13:11 UTCEPSS rescore
  58. 2026-06-02 20:12 UTCEPSS rescore
  59. 2026-06-02 20:12 UTCEPSS rescore
  60. 2026-06-01 13:51 UTCEPSS rescore
  61. 2026-06-01 13:51 UTCEPSS rescore
  62. 2026-06-01 13:51 UTCEPSS rescore
  63. 2026-05-31 22:30 UTCEPSS rescore
  64. 2026-05-31 22:30 UTCEPSS rescore
  65. 2026-05-31 00:16 UTCEPSS rescore
  66. 2026-05-31 00:16 UTCEPSS rescore
  67. 2026-05-29 13:43 UTCEPSS rescore
  68. 2026-05-28 13:44 UTCEPSS rescore
  69. 2026-05-28 13:44 UTCEPSS rescore
  70. 2026-05-28 13:44 UTCEPSS rescore
  71. 2026-05-27 13:40 UTCEPSS rescore
  72. 2026-05-27 13:40 UTCEPSS rescore
  73. 2026-05-23 16:05 UTCEG score recompute
  74. 2026-05-23 16:05 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2024-56431?
CVE-2024-56431 is a critical vulnerability published on December 25, 2024. ochufftree_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.
When was CVE-2024-56431 disclosed?
CVE-2024-56431 was first published in the National Vulnerability Database on December 25, 2024, with the most recent update on April 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2024-56431 actively exploited?
CVE-2024-56431 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 23.1% of all scored CVEs.
What is the CVSS score of CVE-2024-56431?
CVE-2024-56431 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2024-56431?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2024-56431, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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