CVE-2025-66305Public exploitNetwork attack vector

Site-wide denial of service via regex injection

Published Dec 1, 2025 · Updated Dec 2, 2025

Denial of service in GetGrav Grav before 1.8.0-beta.27 allows remote authenticated users to crash the site via a malformed language value. Language::setActiveFromUri builds a preg_match expression from the Supported language list without safely escaping regex delimiters, so a slash produces a fatal parsing error. Admin-panel permission to save system configuration is required, and the resulting failure affects both public and administrative views.

CVSS severity8.2
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in GetGrav Grav before 1.8.0-beta.27 allows remote authenticated users to crash the site via a malformed language value. Language::setActiveFromUri builds a preg_match expression from the Supported language list without safely escaping regex delimiters, so a slash produces a fatal parsing error. Admin-panel permission to save system configuration is required, and the resulting failure affects both public and administrative views.

The record

CVE
CVE-2025-66305
Published
Dec 1, 2025
Updated
Dec 2, 2025
Vendor
GetGrav
Product
Grav
Classifications
CWE-248, CWE-20, T1499.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.8.0-beta.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

GetGrav · Gravversion=< 1.8.0-beta.27

Published CVSS scores

4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
8.2GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-248Uncaught Exception
CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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