CVE-2026-12773

CRITICALNVD 9.87.3▼
EchelonGraph scoreMEDIUM confidence

Score 7.3 from GitHub Security Advisory published 2026-06-21. NVD baseline CVSS 9.8; sources differ by 2.5.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0

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

A weakness has been identified in BerriAI litellm up to 1.59.8. Affected is the function UserAPIKeyAuth of the file litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py of the component MCP Proxy. Executing a manipulation can lead to improper authentication. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure.

CVSS v3
9.8
EG Score
7.3(medium)
EPSS
45.6%
KEV
Not listed

Published

June 21, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 16, 2026
Patch available. Sources: redhat.
redhat
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12773.json
redhat

2491112 – (CVE-2026-12773) CVE-2026-12773 litellm: BerriAI litellm: Improper authentication in MCP Proxy via UserAPIKeyAuth function

https://bugzilla.redhat.com/show_bug.cgi?id=2491112
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-12773
generic

Critical Authentication Bypass and Privilege Escalation via Exception Swallowing in MCP Proxy · GitHub

https://gist.github.com/YLChen-007/3cfaad10a69d7a15e4d4d458cb53309e

Vendor Advisories for CVE-2026-12773(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 80× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 02:28 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-17 00:41 UTCGHSA enrichment
  8. 2026-07-16 17:02 UTCEPSS rescore
  9. 2026-07-16 11:26 UTCGHSA enrichment
  10. 2026-07-15 22:25 UTCGHSA enrichment
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 09:23 UTCGHSA enrichment
  13. 2026-07-15 02:26 UTCNVD updateCVSS v3 → 9.8 · CVSS v4 → 5.5 · severity → CRITICAL
  14. 2026-07-15 02:06 UTCMITRE cvelistV5CVSS v3 → 7.3 · CVSS v4 → 6.9 · severity → HIGH
  15. 2026-07-15 02:00 UTCEPSS rescore
  16. 2026-07-14 20:16 UTCGHSA enrichment
  17. 2026-07-14 07:14 UTCGHSA enrichment
  18. 2026-07-13 22:30 UTCEPSS rescore
  19. 2026-07-13 18:13 UTCGHSA enrichment
  20. 2026-07-13 06:12 UTCEPSS rescore
  21. 2026-07-13 05:00 UTCGHSA enrichment
  22. 2026-07-12 15:58 UTCGHSA enrichment
  23. 2026-07-12 05:46 UTCEPSS rescore
  24. 2026-07-12 02:57 UTCGHSA enrichment
  25. 2026-07-11 13:56 UTCGHSA enrichment
Show 62 more
  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-11 00:54 UTCGHSA enrichment
  3. 2026-07-10 11:52 UTCGHSA enrichment
  4. 2026-07-09 22:36 UTCGHSA enrichment
  5. 2026-07-09 19:10 UTCEPSS rescore
  6. 2026-07-09 09:34 UTCGHSA enrichment
  7. 2026-07-08 20:33 UTCGHSA enrichment
  8. 2026-07-08 15:15 UTCEPSS rescore
  9. 2026-07-08 15:15 UTCEPSS rescore
  10. 2026-07-08 07:31 UTCGHSA enrichment
  11. 2026-07-07 18:29 UTCGHSA enrichment
  12. 2026-07-07 13:46 UTCEPSS rescore
  13. 2026-07-07 01:16 UTCGHSA enrichment
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 12:15 UTCGHSA enrichment
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-05 23:02 UTCGHSA enrichment
  18. 2026-07-05 09:58 UTCGHSA enrichment
  19. 2026-07-05 02:30 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 20:56 UTCGHSA enrichment
  22. 2026-07-04 07:55 UTCGHSA enrichment
  23. 2026-07-04 06:31 UTCEPSS rescore
  24. 2026-07-03 18:54 UTCGHSA enrichment
  25. 2026-07-03 05:53 UTCGHSA enrichment
  26. 2026-07-02 16:51 UTCGHSA enrichment
  27. 2026-07-02 03:49 UTCGHSA enrichment
  28. 2026-07-01 15:06 UTCEPSS rescore
  29. 2026-07-01 15:06 UTCEPSS rescore
  30. 2026-07-01 14:47 UTCGHSA enrichment
  31. 2026-07-01 01:45 UTCGHSA enrichment
  32. 2026-06-30 23:22 UTCEPSS rescore
  33. 2026-06-30 12:43 UTCGHSA enrichment
  34. 2026-06-29 23:36 UTCGHSA enrichment
  35. 2026-06-29 14:06 UTCEPSS rescore
  36. 2026-06-29 10:35 UTCGHSA enrichment
  37. 2026-06-28 21:33 UTCGHSA enrichment
  38. 2026-06-28 14:07 UTCEPSS rescore
  39. 2026-06-28 08:32 UTCGHSA enrichment
  40. 2026-06-28 04:56 UTCEPSS rescore
  41. 2026-06-28 04:56 UTCEPSS rescore
  42. 2026-06-27 19:30 UTCGHSA enrichment
  43. 2026-06-27 06:29 UTCGHSA enrichment
  44. 2026-06-27 03:08 UTCEPSS rescore
  45. 2026-06-26 17:27 UTCGHSA enrichment
  46. 2026-06-26 04:26 UTCGHSA enrichment
  47. 2026-06-25 15:22 UTCGHSA enrichment
  48. 2026-06-25 13:49 UTCEPSS rescore
  49. 2026-06-25 02:20 UTCGHSA enrichment
  50. 2026-06-24 22:03 UTCNVD updateCVSS v3 → 9.8 · severity → CRITICAL
  51. 2026-06-24 14:05 UTCEPSS rescore
  52. 2026-06-24 13:18 UTCGHSA enrichment
  53. 2026-06-24 00:17 UTCGHSA enrichment
  54. 2026-06-23 21:32 UTCEPSS rescore
  55. 2026-06-23 11:13 UTCGHSA enrichment
  56. 2026-06-22 22:10 UTCGHSA enrichment
  57. 2026-06-22 17:45 UTCNVD updateCVSS v4 → 5.5 · severity → HIGH
  58. 2026-06-22 09:08 UTCGHSA enrichment
  59. 2026-06-21 20:06 UTCGHSA enrichment
  60. 2026-06-21 07:02 UTCEG score recompute
  61. 2026-06-21 07:02 UTCGHSA enrichment
  62. 2026-06-21 07:01 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-12773?
CVE-2026-12773 is a critical vulnerability published on June 21, 2026. A weakness has been identified in BerriAI litellm up to 1.59.8. Affected is the function UserAPIKeyAuth of the file litellm/proxy/experimental/mcpserver/auth/userapikeyauthmcp.py of the component MCP Proxy. Executing a manipulation can lead to improper authentication. The attack may be launched…
When was CVE-2026-12773 disclosed?
CVE-2026-12773 was first published in the National Vulnerability Database on June 21, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12773 actively exploited?
CVE-2026-12773 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 45.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12773?
CVE-2026-12773 has a CVSS v3 base score of 9.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.3.
How do I remediate CVE-2026-12773?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12773, 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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