EUVD-2026-65333
GHSA-7mp3-wcqf-gf22
Severity by source
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-reachable with no privileges or interaction required; only integrity is impacted as topic content is overwritten, with no confidentiality or availability consequence.
Primary rating from Vendor (TYPO3).
CVSS VectorVendor: TYPO3
CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
3DescriptionCVE.org
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.
AnalysisAI
Missing server-side ownership verification in the TYPO3 Forum extension allows any unauthenticated visitor to overwrite the content of any forum topic. Because topic identifiers are enumerable from the public forum listing, an attacker needs no credentials, special access, or non-default configuration to target arbitrary topics. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | No special conditions are required. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N) reflects a straightforward, network-reachable flaw requiring no attack prerequisites, no authentication, and no user interaction - placing it firmly in the high-priority tier for any TYPO3 deployment running the Forum extension. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker browses the public forum, collects topic identifiers from the listing page, and selects a target post such as a pinned announcement or a support thread. Using browser developer tools or an HTTP proxy, the attacker captures a valid edit request, substitutes the target topic's identifier, and submits crafted replacement content - the server applies the change without any ownership verification. … |
| Remediation | Consult the TYPO3 Security Advisory at https://typo3.org/security/advisory/typo3-ext-sa-2026-021 for the patched release version and upgrade immediately. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours: Inventory all TYPO3 deployments using the Forum extension and classify by criticality and exposure (public-facing vs. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Same weakness CWE-862 – Missing Authorization
View allSame technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today