CVE-2026-84461: Zammad: Missing rate limiting allows password brute-forcing during two-factor login

Severity: medium (CVSS 6.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-09-28
Weakness: CWE-203

Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, the two-factor login step let an attacker try unlimited password guesses for any account without triggering Zammad's normal lockout or rate limiting. The response also revealed whether a guess was correct, even before two-factor authentication was checked. This made it possible to brute-force weak or reused passwords. This issue is fixed in version 7.1.2.

Affected products

zammad: before 7.1.2

References

https://github.com/zammad/zammad/commit/d51254f1c6da13f6ee27636a5c82e53f7e59666b
https://github.com/zammad/zammad/security/advisories/GHSA-6vh5-pfp2-5rmh

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