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CVE-2026-62237

MEDIUM 6 PoC AVAILABLE ALL-YEARS

Published 2026-07-17 · Last modified 2026-07-21 · VulnCheck · NVD: Deferred

Grav before 2.0.4 contains a regular expression denial of service (ReDoS) vulnerability in the regex_replace filter and function, which are allowlisted in the Twig content sandbox. When Twig processing in page content is enabled (security.twig_content.process_enabled: true, disabled by default), an authenticated page editor can supply a catastrophically backtracking PCRE pattern that is passed directly to PHP's preg_replace(), causing unbounded CPU consumption and denial of service to the web server process.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. The barrier to attack is reduced — watch closely.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 17th percentile

○ In CISA KEV● Public exploit / PoC◆ SSVC: exploitation poc, automatable no

Impact if exploited

6CVSS 4.0 · MEDIUM · CNA

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityHigh

What an attacker needs

  • Access: Reachable over the network — no local access needed
  • Privileges: Requires a low-privilege account
  • User interaction: No user interaction needed
  • Complexity: No special conditions — reliably repeatable
  • Requirements: Specific conditions must be present

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-62237/poc.jsonMachine-readable PoC index for this CVE (for automation).

For defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-62237/poc.json

Affected

Vendors Getgrav

Products Grav

Weakness (CWE)

  • CWE-1333: Inefficient Regular Expression Complexity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

All CVSS metrics

  • MEDIUM 6 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
  • MEDIUM 6.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  • MEDIUM 6 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/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
  • MEDIUM 6.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Sources: NVD · CVE.org · EPSS