CVE-2026-45185 | Exim before 4.99.3, in certain GnuTLS configurations, has a … | CVSS 9.8 CRITICAL

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.

Metadata

CVE ID: CVE-2026-45185
State: PUBLISHED
Assigner: mitre
Reserved: 2026-05-10 00:00 UTC
Published: 2026-05-12 00:00 UTC
Last updated: 2026-05-14 03:55 UTC
Primary CWE: CWE-416
CWE-416 Use After Free
Vendor / Product: Exim / Exim
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
Exim	Exim	—	4.97 < 4.99.3

Weakness (CWE)

CWE	Source	Description
CWE-416	cna	CWE-416 Use After Free

CVSS scores (1)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References (7)