VulnerabilityDeferred

CVE-2026-77143

The frontend topic editing flow does not verify on the server side that the requesting visitor owns the topic being modified.

HIGH 8.8EPSS 0.24%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The frontend topic editing flow does not verify on the server side that the requesting visitor owns the topic being modified. As a result, a visitor who knows the identifier of a topic from the public forum can submit a modified update request for that topic directly and overwrite its content, without the application confirming ownership. Topic identifiers are visible in the public forum listing, and exploitation requires no privileged access or non-default configuration.

CVSS 4.0: 8.8 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.24% probability · 15th percentile
CISA KEV: Not listed
Weakness: CWE-639, CWE-862
Source: f4fb688c-4412-4426-b4b8-421ecf27b14a

References

https://typo3.org/security/advisory/typo3-ext-sa-2026-021

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.