CVE-2026-8727: Remote Code Execution in extension "Site Crawler" (crawler)
Vulnerability summary
CVE-2026-8727 is a high (CVSS 7.1) Deserialization of Untrusted Data vulnerability in typo3 extension "site crawler". EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 33.1% of scored vulnerabilities.
Not severe (CVSS 7.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 19-05-2026PublishedVulnerability first disclosed.
- 19-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST7.1HighCVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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
EPSS trend
Probability
0.39%
Chance of exploitation in the next 30 days
Percentile
33%
Versus all other CVEs
30-day change
Decrease -0.11 pp
From 0.50% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, administrative account, user interaction (CVSS vector). Other conditions: not stated in public data.
Typo31 product
- extension "site crawler"≥ 12.0.0, < 12.0.11 | < 11.0.13
1 vendor · 1 product
References
1 links- typo3.org/security/advisory/typo3-ext-sa-2026-008Vendor Advisory