CVE-2026-45185

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-12. NVD baseline CVSS 9.8; sources differ by 0.0.

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

A fix is available — apply it.

Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
65.4%
KEV
Not listed

Published

May 12, 2026

Last Modified

May 28, 2026

Advisory Details (7)

Auto-updated Jun 20, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

oss-security - Re: [EXIM-Security-2026-05-01.1] Security Release 4.99.3

http://www.openwall.com/lists/oss-security/2026/05/12/25
generic🔴 Active Exploitation

XBOW - Dead.Letter (CVE-2026-45185) How XBOW Found an Unauthenticated RCE on Exim

https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim
generic

oss-security - [EXIM-Security-2026-05-01.1] Security Release 4.99.3

https://www.openwall.com/lists/oss-security/2026/05/12/4
generic

Dead.Letter (CVE-2026-45185) – How XBOW found an unauthenticated RCE on Exim | Hacker News

https://news.ycombinator.com/item?id=48111748
generic

Index of /static/doc/security/EXIM-Security-2026-05-01.1/

https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/
generic

Exim Internet Mailer

https://exim.org
generic

EximSecurity - exim/wiki - Exim Forgejo

https://code.exim.org/exim/wiki/wiki/EximSecurity

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntueximon4 (4.86.2-2ubuntu2.6+esm9) @ xenial2026-06-28ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 7× in last 7d / 48× 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 250 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCliamromanis101/Dead.Letter-CVE-2026-45185
    First seen May 12, 2026

    Dead.Letter CVE-2026-45185 EXIM Vulnerability Detection Script

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-45185?
CVE-2026-45185 is a critical vulnerability published on May 12, 2026. Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to…
When was CVE-2026-45185 disclosed?
CVE-2026-45185 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45185 actively exploited?
CVE-2026-45185 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 65.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45185?
CVE-2026-45185 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-45185?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45185, 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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