CVE-2026-102374 PUBLISHED

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

Assigner: VulnCheck
Reserved: 28.09.2026 Published: 29.09.2026 Updated: 29.09.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	Low
Attack Complexity	Low	Integrity	None	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS Score: 6.1

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	GestSup
Product	GestSup
Versions	Default: unaffected affected from 0 to 3.2.62 (excl.)

Credits

SpiizN finder

References

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE