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HIGH

CVE-2025-47947

ModSecurity Has Possible DoS Vulnerability

CVSS v3

7.5

HIGH

EPSS Score

0.6 %

exploit probability, as of 2026-10-18

CISA KEV

No

known exploited

Exploitation

poc

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • modsecurityBitnamiall versions · fixed in 3.0.12
  • modsecurity2Bitnamiall versions · fixed in 2.9.9
  • mod_securityAlmaLinux:9all versions · fixed in 2.9.6-2.el9_6and 1 other package
  • mod_securityAlmaLinux:8all versions · fixed in 2.9.6-2.el8_10and 1 other package

Vendor advisories

  • CVE-2025-47947 Red Hat Product Security224 products fixed

    modsecurity: ModSecurity Has Possible DoS Vulnerability

  • RHSA-2025:13681 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update

  • RHSA-2025:13680 Red Hat Product Security57 products fixed

    Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update

  • RHSA-2025:8937 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: mod_security security update

  • RHSA-2025:8917 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: mod_security security update

  • RHSA-2025:8922 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: mod_security security update

6 more advisories

Full record on NVD

Description

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Versions up to and including 2.9.8 are vulnerable to denial of service in one special case (in stable released versions): when the payload's content type is `application/json`, and there is at least one rule which does a `sanitiseMatchedBytes` action. A patch is available at pull request 3389 and expected to be part of version 2.9.9. No known workarounds are available.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2025-05-21
Last Modified
2025-06-20

Frequently asked questions

What is CVE-2025-47947?

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Versions up to and including 2.9.8 are vulnerable to denial of service in one special case (in stable released versions): when the payload's content type is `application/json`, and there is at least one rule which does a `sanitiseMatchedBytes` action. A patch is available at pull request 3389 and expected to be part of version 2.9.9. No known workarounds are available.

Is CVE-2025-47947 actively exploited?

A proof-of-concept exploit exists for CVE-2025-47947, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2025-47947?

CVE-2025-47947 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Same product first, then the same vendor advisory and the same publication week.

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