CVE-2026-102374

EUVD-2026-88598
GestSup versions before 3.2.62 contain a stored cross-site scripting vulnerability in the IMAP OAuth connector that double-decodes MIME-encoded email subjects after HTML escaping. Unauthenticated attackers can send crafted emails to monitored mailboxes with nested MIME encoded-words to inject JavaScript that executes in technician sessions when viewing tickets.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
6.1 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 10.21%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
gestsupgestsup
𝑥
< 3.2.62
CNA
Common Weakness Enumeration
References
https://gestsup.fr/index.php?page=changelog
https://gestsup.fr/index.php?page=download
https://gestsup.fr/index.php?page=download&channel=stable&version=3.2.62&type=patch
https://www.vulncheck.com/advisories/gestsup-before-3.2.62-stored-xss-via-double-decoded-email-subject-in-oauth-imap-connector