Threat Intelligence / CVE / CVE-2026-45185

CVE-2026-45185 — Exim

CVSS v3.1 9.8 (CRITICAL) · EPSS 0.0% (higher than 24.9% of all scored CVEs) · Priority 5.9/10 · Published 2026-05-12

As of 2026-05-14, CVE-2026-45185 is a CRITICAL-severity vulnerability in Exim, CVSS v3.1 9.8, EPSS 0.0% (24.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-45185, most recently “Dead.Letter — CVE-2026-45185 Unauthenticated Pre-Auth RCE in Exim via Use-After-Free in BDAT/GnuTLS”.

Last updated: 2026-05-14

What is CVE-2026-45185?

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.

The record classifies CVE-2026-45185 under weakness class CWE-416. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 123 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
0.0% probability of exploitation in the next 30 days, higher than 24.9% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
5.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-05-12, last modified 2026-05-14

Is CVE-2026-45185 being exploited?

It currently carries a trending score of 11 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-45185

No vendor patch reference has been recorded for CVE-2026-45185 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-45185

1 tracked threat in the Threadlinqs corpus references CVE-2026-45185, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-45185 are available via the Threadlinqs MCP server (Purple tier). View plans →

← all vulnerabilities · Markdown version · Threadlinqs Intelligence