CVE-2026-43994

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

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

Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.10.0 contain a stack buffer overflow in decode_oauth_token_gcm(). A uint16_t nonce_len field read from an attacker-supplied OAuth access token (0-65535) is passed directly to memcpy() as the copy length into a 256-byte stack buffer (oauth_encrypted_block.nonce[256]) without bounds checking. The overflow occurs before AES-GCM authentication is verified, the attacker does not need to know the OAuth key or produce a valid AES-GCM token. Up to 735 bytes of attacker-controlled data are written past the buffer, may corrupt adjacent stack data, including control-flow data depending on compiler, ABI, and mitigations. Requires --oauth mode (non-default). This may provide a plausible RCE primitive depending on exploit mitigations; because coturn is widely deployed for WebRTC TURN/STUN and --oauth is commonly recommended, impact can be broad. This issue has been fixed in version 4.10.0.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
36.3%
KEV
Not listed

Published

June 18, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jul 12, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available

Stack buffer overflow in decode_oauth_token_gcm() · Advisory · coturn/coturn · GitHub

https://github.com/coturn/coturn/security/advisories/GHSA-74pg-rfh2-5qw5
github_release Patch Available

4.10.0

Patch available: coturn/coturn 4.10.0

https://github.com/coturn/coturn/releases/tag/4.10.0

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 48× in last 7d / 156× 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.

Showing the most recent 100 of 156 total refreshes for this CVE.

  1. 2026-07-16 00:56 UTCEG score recompute
  2. 2026-07-15 20:59 UTCEG score recompute
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 16:48 UTCEG score recompute
  5. 2026-07-15 12:49 UTCEG score recompute
  6. 2026-07-15 06:31 UTCEG score recompute
  7. 2026-07-15 02:00 UTCEPSS rescore
  8. 2026-07-15 01:04 UTCEG score recompute
  9. 2026-07-14 21:06 UTCEG score recompute
  10. 2026-07-14 17:09 UTCEG score recompute
  11. 2026-07-14 13:12 UTCEG score recompute
  12. 2026-07-14 09:15 UTCEG score recompute
  13. 2026-07-14 05:17 UTCEG score recompute
  14. 2026-07-14 01:15 UTCEG score recompute
  15. 2026-07-13 22:30 UTCEPSS rescore
  16. 2026-07-13 21:18 UTCEG score recompute
  17. 2026-07-13 17:20 UTCEG score recompute
  18. 2026-07-13 13:23 UTCEG score recompute
  19. 2026-07-13 09:26 UTCEG score recompute
  20. 2026-07-13 06:13 UTCEPSS rescore
  21. 2026-07-13 05:29 UTCEG score recompute
  22. 2026-07-13 01:32 UTCEG score recompute
  23. 2026-07-12 21:36 UTCEG score recompute
  24. 2026-07-12 17:00 UTCEG score recompute
  25. 2026-07-12 12:57 UTCEG score recompute
Show 75 more
  1. 2026-07-12 09:00 UTCEG score recompute
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-12 05:03 UTCEG score recompute
  4. 2026-07-12 01:05 UTCEG score recompute
  5. 2026-07-11 21:07 UTCEG score recompute
  6. 2026-07-11 17:11 UTCEG score recompute
  7. 2026-07-11 13:13 UTCEG score recompute
  8. 2026-07-11 09:16 UTCEG score recompute
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-11 05:20 UTCEG score recompute
  11. 2026-07-11 01:23 UTCEG score recompute
  12. 2026-07-10 21:14 UTCEG score recompute
  13. 2026-07-10 17:17 UTCEG score recompute
  14. 2026-07-10 13:19 UTCEG score recompute
  15. 2026-07-10 09:23 UTCEG score recompute
  16. 2026-07-10 05:24 UTCEG score recompute
  17. 2026-07-10 01:10 UTCEG score recompute
  18. 2026-07-09 20:49 UTCEG score recompute
  19. 2026-07-09 19:10 UTCEPSS rescore
  20. 2026-07-09 16:53 UTCEG score recompute
  21. 2026-07-09 12:53 UTCEG score recompute
  22. 2026-07-09 08:54 UTCEG score recompute
  23. 2026-07-09 04:55 UTCEG score recompute
  24. 2026-07-09 00:56 UTCEG score recompute
  25. 2026-07-08 20:58 UTCEG score recompute
  26. 2026-07-08 17:02 UTCEG score recompute
  27. 2026-07-08 15:16 UTCEPSS rescore
  28. 2026-07-08 13:06 UTCEG score recompute
  29. 2026-07-08 07:42 UTCEG score recompute
  30. 2026-07-08 03:46 UTCEG score recompute
  31. 2026-07-07 23:48 UTCEG score recompute
  32. 2026-07-07 19:52 UTCEG score recompute
  33. 2026-07-07 13:46 UTCEPSS rescore
  34. 2026-07-07 12:15 UTCEG score recompute
  35. 2026-07-07 08:13 UTCEG score recompute
  36. 2026-07-07 02:56 UTCEG score recompute
  37. 2026-07-06 22:59 UTCEG score recompute
  38. 2026-07-06 19:01 UTCEG score recompute
  39. 2026-07-06 16:27 UTCEPSS rescore
  40. 2026-07-06 13:52 UTCEG score recompute
  41. 2026-07-06 09:39 UTCEG score recompute
  42. 2026-07-06 05:24 UTCEG score recompute
  43. 2026-07-06 02:23 UTCEPSS rescore
  44. 2026-07-06 01:25 UTCEG score recompute
  45. 2026-07-05 21:28 UTCEG score recompute
  46. 2026-07-05 17:31 UTCEG score recompute
  47. 2026-07-05 13:34 UTCEG score recompute
  48. 2026-07-05 09:37 UTCEG score recompute
  49. 2026-07-05 05:40 UTCEG score recompute
  50. 2026-07-05 02:30 UTCEPSS rescore
  51. 2026-07-05 01:17 UTCEG score recompute
  52. 2026-07-04 21:08 UTCEG score recompute
  53. 2026-07-04 17:11 UTCEG score recompute
  54. 2026-07-04 13:14 UTCEG score recompute
  55. 2026-07-04 09:18 UTCEG score recompute
  56. 2026-07-04 06:31 UTCEPSS rescore
  57. 2026-07-04 05:20 UTCEG score recompute
  58. 2026-07-04 01:22 UTCEG score recompute
  59. 2026-07-03 21:24 UTCEG score recompute
  60. 2026-07-03 17:28 UTCEG score recompute
  61. 2026-07-03 13:30 UTCEG score recompute
  62. 2026-07-03 09:33 UTCEG score recompute
  63. 2026-07-03 05:36 UTCEG score recompute
  64. 2026-07-03 01:35 UTCEG score recompute
  65. 2026-07-02 21:39 UTCEG score recompute
  66. 2026-07-02 17:42 UTCEG score recompute
  67. 2026-07-02 13:36 UTCEG score recompute
  68. 2026-07-02 09:39 UTCEG score recompute
  69. 2026-07-02 05:42 UTCEG score recompute
  70. 2026-07-02 01:45 UTCEG score recompute
  71. 2026-07-01 21:48 UTCEG score recompute
  72. 2026-07-01 17:51 UTCEG score recompute
  73. 2026-07-01 15:07 UTCEPSS rescore
  74. 2026-07-01 13:52 UTCEG score recompute
  75. 2026-07-01 09:55 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-43994?
CVE-2026-43994 is a critical vulnerability published on June 18, 2026. Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.10.0 contain a stack buffer overflow in decodeoauthtokengcm(). A uint16t noncelen field read from an attacker-supplied OAuth access token (0-65535) is passed directly to memcpy() as the copy length into a…
When was CVE-2026-43994 disclosed?
CVE-2026-43994 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43994 actively exploited?
CVE-2026-43994 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 36.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43994?
CVE-2026-43994 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-43994?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43994, 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-43994

Explore →

Is Your Infrastructure Affected by CVE-2026-43994?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs