CVE-2026-40685
criticalpriority · track · 39EPSS 0.003 · 25 %ileDEEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 6.5–9.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (29)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-1334Exim und cPanel/WHM: Mehrere SchwachstellenDeutsch2026-05-03csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Exim und cPanel cPanel/WHM ausnutzen, um einen Denial of Service Angriff durchzuführen, Daten zu manipulieren oder vertrauliche Informationen offenzulegen.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://exim.org/Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-40685cnnvd
- https://code.exim.org/exim/exim/commit/9fdc057e71b87c87a0d3d2288b2810a0efaaba57enisa_euvd
- https://exim.org/static/doc/security/CVE-2026-40685.txtenisa_euvd
- https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40685.assessmentenisa_euvd
- https://www.openwall.com/lists/oss-security/2026/04/30/21enisa_euvd
- https://code.exim.org/exim/exim/commit/9fdc057e71b87c87a0d3d2288b2810a0efaaba57Patchnvd
- https://exim.org/static/doc/security/CVE-2026-40685.txtBroken Linknvd
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