CVE-2026-58655 json
Grav Flex Objects - Server-Side Template Injection via Dynamic Titles
published 2026-07-15 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-44633
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.4%
- EPSS 1.4% chance of exploitation in 30 days, percentile 72%
- public exploits
- 0
- none known
Summary
The bundled Grav Flex Objects plugin (getgrav/grav-plugin-flex-objects) before 1.4.0 contains a stored server-side template injection vulnerability. When rendering dynamic collection or object titles, the plugin passes user-controlled frontmatter values (page.header.flex.collection.title or page.header.flex.object.title) to Twig's template_from_string(), causing them to be evaluated as Twig code rather than treated as text. This path bypasses Grav's Security::cleanDangerousTwig() sanitization. An attacker who can control the title frontmatter of a publicly reachable Flex Objects page can achieve arbitrary Twig execution and escalate to remote command execution via access to internal Grav services such as the scheduler.
Patch / fix
- getgrav grav 1.4.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
1.42% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/getgrav/grav/security/advisories/GHSA-623v-m3c4-3pw8 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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 |
Affected products
- getgrav grav
Classification
- Weakness
-
- CWE-94 Improper Control of Generation of Code
References
-
github.com
/getgrav/grav/security/advisories/GHSA-623v-m3c4-3pw8
vendor-advisory, exploit
-
vulncheck.com
/advisories/grav-flex-objects-server-side-template-injection-via-dynamic-titles
third-party-advisory
Sources
- CVE List CVE-2026-58655
- NVD CVE-2026-58655
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