What is CVE-2026-66141?
Exim before 4.99.5 allows .forward privilege escalation because force_command for a pipe transport is mishandled.
The record classifies CVE-2026-66141 under weakness class CWE-829. Its CVSS v3 base vector states that the flaw requires local access to the host, 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 96 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.4 — HIGH
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 0.1% probability of exploitation in the next 30 days, higher than 2.9% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-24
Is CVE-2026-66141 being exploited?
It currently carries a trending score of 16 in the Threadlinqs vulnerability feed.
Affected products and versions
- Exim: Exim
How to fix CVE-2026-66141
No vendor patch reference has been recorded for CVE-2026-66141 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-2026-66141
1 tracked threat in the Threadlinqs corpus references CVE-2026-66141, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .