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TI-2026-33005 Aliases CVE-2026-45185GHSA-fhg4-whcv-f8v4

Use after free in Exim

Priority MEDIUM 51CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0127 69th percentileScored 2026-11-07
Fix Fixed Exim (Exim): 4.99.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
EximExim4.97 to before 4.99.34.99.3Patch availableCNA
  • Exim VendorExim Affected 4.97 to before 4.99.3 Fixed in 4.99.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*4.97 to before 4.99.3VulnerableExim
  • cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:* Versions 4.97 to before 4.99.3 Vulnerable ·Exim

Remediation

  • Fix · CNA Exim (Exim) Fixed in 4.99.3

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45185
  2. 2026-10-03 Alias added: GHSA-fhg4-whcv-f8v4

References

Advisory 4

Other 4

  • TI-2019-12627 Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than… KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-07471 OS command injection in exim KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-04965 An issue was discovered in the base64d function in the SMTP listener in Exim before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2010-04077 Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70… KEVCVSS 3.1CRITICAL 9.8
  • TI-2010-04078 Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of… KEVCVSS 3.1HIGH 7.8
  • TI-2025-19707 SQL injection in Exim CVSS 3.1CRITICAL 9.8
See all 69 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences