CVE-2026-45185

Published May 12, 2026 CVSS 3.1 · 9.8 Critical EPSS 1.3% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8382-1 Exim vulnerabilities
History
Type Values Removed Values Added
Title Remote Use‑After‑Free in Exim Enables Arbitrary Code Execution
Type Values Removed Values Added
Title Remote Use‑After‑Free in Exim Enables Arbitrary Code Execution
Type Values Removed Values Added
Title Use‑After‑Free Leading to Remote Code Execution in BDAT Parsing of Exim
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Use‑After‑Free Leading to Remote Code Execution in BDAT Parsing of Exim
Type Values Removed Values Added
First Time appeared Exim
Exim exim
Weaknesses CWE-416
CPEs cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
Vendors & Products Exim
Exim exim
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Description 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.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 14, 2026, 3:55 AM
Reserved
May 10, 2026, 12:00 AM
Status
Analyzed
Published
May 12, 2026, 8:16 PM
Modified
Nov 11, 2026, 8:10 PM