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CVE-2026-84463

Zammad: Stored HTML injection in Knowledge Base video widget enables forced session switching via unescaped iframe attribute

No known exploitation. EPSS puts it in the 4th percentile. No fix published yet.

CVSS —Not scoredEPSS percentile4th0.1% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
No public exploit knownFixNone yetNo fix or workaround published

Published Updated Sources: CVE.org, NVD

NVD CVE.org

What to do

No fixed build or workaround is published yet. Limit exposure and watch for a patch.

  • ZammadAffected: < 7.1.2Upgrade to: not statedStated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

What it is

From the CVE record

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, a user with Knowledge Base editing rights for a category can embed a video widget in a published answer with a specially crafted value. When the answer is rendered, that value is inserted into the page's HTML without being escaped for its attribute context, allowing it to break out and inject additional HTML into the page. When another user who has permission to switch between user sessions views the affected answer, the injected HTML causes their browser to silently send a request to Zammad's session-switching endpoint using their own active credentials. This results in switching their session to an account chosen by the person who wrote the Knowledge Base answer. No action is required from the viewer beyond opening the published answer. This issue is fixed in version 7.1.2.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS4th
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.1% chance of exploitation activity in the next 30 days, which ranks it in the 4th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

6 events over 4 days, from the signal feeds we watch.

  1. Record updated
  2. Record updated
  3. Publishedweakness classified, att&ck mapped, record updated

Affected products

Technical detail

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

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