Medium severity6.5NVD Advisory· Published Apr 30, 2026· Updated Jun 17, 2026
CVE-2026-40685
CVE-2026-40685
Description
In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \ skipping.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
22- osv-coords20 versionspkg:apk/chainguard/eximpkg:apk/chainguard/exim-pgsqlpkg:apk/chainguard/exim-utilspkg:apk/wolfi/exim-sqlitepkg:apk/chainguard/exim-cdbpkg:apk/chainguard/exim-dbmdbpkg:apk/chainguard/exim-sqlitepkg:apk/wolfi/eximpkg:apk/wolfi/exim-dnsdbpkg:apk/wolfi/exim-pgsqlpkg:apk/chainguard/exim-docpkg:apk/wolfi/exim-cdbpkg:apk/chainguard/exim-dnsdbpkg:apk/chainguard/exim-scriptspkg:apk/wolfi/exim-dbmdbpkg:apk/wolfi/exim-docpkg:apk/chainguard/exim-mysqlpkg:apk/wolfi/exim-mysqlpkg:apk/wolfi/exim-utilspkg:apk/wolfi/exim-scripts
< 4.99.5-r0+ 19 more
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
- (no CPE)range: < 4.99.5-r0
Patches
Vulnerability mechanics
References
4- code.exim.org/exim/exim/commit/9fdc057e71b87c87a0d3d2288b2810a0efaaba57nvdPatch
- exim.org/static/doc/security/cve-2026-04.1/CVE2026-40685.assessmentnvdVendor Advisory
- www.openwall.com/lists/oss-security/2026/04/30/21nvdMailing ListThird Party Advisory
- exim.org/static/doc/security/CVE-2026-40685.txtnvdBroken Link
News mentions
1- ⚡ Weekly Recap: AI-Powered Phishing, Android Spying Tool, Linux Exploit, GitHub RCE & MoreThe Hacker News · May 4, 2026