How severe is CVE-2026-8727?

CVE-2026-8727 has a CVSS 4.0 base score of 7.1, rated high severity.

Is CVE-2026-8727 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-8727?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-8727 have an EU (EUVD) identifier?

Yes. CVE-2026-8727 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30854.

When was CVE-2026-8727 published?

CVE-2026-8727 was published on 2026-05-19 and last updated on 2026-06-17.

CVE-2026-8727

CVE-2026-8727 is a high-severity vulnerability with a CVSS 4.0 base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 4.0 base score 7.1)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30854
Weakness: CWE-502
Published: 2026-05-19
Last modified: 2026-06-17

Description

The Crawler extension passes the X-T3Crawler-Meta response header from crawled URLs directly to PHP's unserialize(). An attacker controlling a crawled endpoint can inject arbitrary serialized PHP objects, leading to Remote Code Execution on the TYPO3 server. Exploitation requires administrative privileges to configure a crawler-enabled page and trigger the crawl via a Scheduler task.

Frequently asked questions

What is CVE-2026-8727?: The Crawler extension passes the X-T3Crawler-Meta response header from crawled URLs directly to PHP's unserialize(). An attacker controlling a crawled endpoint can inject arbitrary serialized PHP objects, leading to Remote Code Execution on the TYPO3 server. Exploitation requires administrative privileges to configure a crawler-enabled page and trigger the crawl via a Scheduler task.
How severe is CVE-2026-8727?: CVE-2026-8727 has a CVSS 4.0 base score of 7.1, rated high severity.
Is CVE-2026-8727 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-8727?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-8727 have an EU (EUVD) identifier?: Yes. CVE-2026-8727 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30854.
When was CVE-2026-8727 published?: CVE-2026-8727 was published on 2026-05-19 and last updated on 2026-06-17.

References

https://typo3.org/security/advisory/typo3-ext-sa-2026-008

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