CVE-2026-66141: Exim before 4.99.5 allows .forward privilege escalation because force_command for a pipe transport is mishandled.

highCVSS 7.4CVE-2026-66141

Exim before 4.99.5 allows .forward privilege escalation because force_command for a pipe transport is mishandled.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.4
Published: 2026-07-24
Last updated: 2026-07-30
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-66141

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-661410.10% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-66141	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownDSA-6400-1 exim4 - security updatedebian

Recent advisories for Exim

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

medium[UPDATE] [medium] Exim: Vulnerability allows information disclosurecert-bund · 2026-07-28
medium[UPDATE] [medium] Exim and cPanel/WHM: Multiple vulnerabilitiescert-bund · 2026-07-28
medium[NEW] [medium] Exim: Multiple vulnerabilitiescert-bund · 2026-07-27
highCVE-2026-66140: Exim before 4.99.5 allows directory traversal to access files outside of the spool area, and c…nvd · 2026-07-24
unknownExim security advisory (AV26-737)cccs · 2026-07-22
unknownUSN-8590-1: Exim vulnerabilitiesubuntu · 2026-07-22