CVE-2026-84463

6.3 MEDIUM 0.1% exploit odds Fix listed XSS Browser & mail

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.
Exploit odds: 0.1% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-25 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-29 20:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.1% in the next 30 days (EPSS).
Severity: 6.3 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-25 19:17 UTC
Last modified: 2026-09-29 20:17 UTC
Exploit probability: 0.1% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Deferred

Attack profile CVSS 4.0 · 6.3

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: Low
User interaction: Passive
Confidentiality: None
Integrity: None
Availability: None

Raw vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-84463.md and follow it. Check whether this project is affected by CVE-2026-84463. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record