CVE-2026-102374 GestSup before 3.2.62 Stored XSS via Double-Decoded Email Subject in OAuth IMAP Connector
Unauthenticated attackers can inject JavaScript via crafted emails, leading to code execution in technician sessions within GestSup.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-102374?
CVE-2026-102374 is a medium-severity cross-site scripting vulnerability in GestSup, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-102374?
How do I fix CVE-2026-102374?
No fix has been published for CVE-2026-102374 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-102374 being exploited?
There is no known exploitation of CVE-2026-102374 in the wild and no public exploit code.
Sources
Also known as GHSA-rhv9-26qc-872f.