CVE-2026-77138
Attacker-controlled cookie leads to PHP object injection and RCE in a TYPO3 extension.
Is CVE-2026-77138 being exploited?
Not confirmed. CVE-2026-77138 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.42% probability of exploitation in the next 30 days.
How severe is CVE-2026-77138?
CVE-2026-77138 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-77138?
Yes. A fix has been recorded for CVE-2026-77138. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-77138 affect?
CVE-2026-77138 affects TYPO3 CMS, Vulnerable TYPO3 extension (unspecified), PHP web servers running the extension. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-77138?
Disable the extension or block malicious cookies, apply vendor patch when released, deploy WAF rules.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can send a crafted cookie to trigger PHP Object Injection and achieve remote code execution on affected TYPO3 servers.
Immediate action required
- affected<= 0.2.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.