CVE-2026-102374

GestSup before 3.2.62 Stored XSS via Double-Decoded Email Subject in OAuth IMAP Connector

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.

Affected

GestSup

CVSS v4.0 VULNCHECK

5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 VULNCHECK

6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

0.21% chance of exploitation in the next 30 days, 11th percentile

Published

2026-09-29

Updated

2026-09-30

Proof-of-concept exploits (2)

• https://blog.spiizn.xyz/articles/remote-code-execution-turning-a-ticket-into-a-new-issue/
• SpiizN/cves1★ · 2026-10-08

References

• CVE Record
• NVD entry

Related

• CVE-2026-100389
• CVE-2026-102372
• CVE-2026-102373