CVE-2025-27110: Libmodsecurity is one component of the ModSecurity v3 project

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2025-27110 is a high-severity flaw (CVSS 7.5) affecting modsecurity. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Libmodsecurity is one component of the ModSecurity v3 project. The library codebase serves as an interface to ModSecurity Connectors taking in web traffic and applying traditional ModSecurity processing. A bug that exists only in Libmodsecurity3 version 3.0.13 means that, in 3.0.13, Libmodsecurity3 can't decode encoded HTML entities if they contains leading zeroes. Version 3.0.14 contains a fix. No known workarounds are available.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-172
Published	2025-02-25
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: trustwave

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-02-25 20:15 UTCPublished CVE record published
2026-06-17 09:03 UTCUpdated Record last modified

trustwave modsecurity DOWNGRADE

Affected: 3.0.13

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.13

1. Check installed version

apt-cache policy modsecurity || rpm -q modsecurity || modsecurity --version

2. No fixed release: DOWNGRADE to a release before 3.0.13 (Debian / Ubuntu)

apt-cache madison modsecurity sudo apt install modsecurity=<VERSION_BEFORE_3.0.13> sudo apt-mark hold modsecurity

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list modsecurity sudo dnf downgrade modsecurity-<VERSION_BEFORE_3.0.13> sudo dnf versionlock add modsecurity

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-27110?

modsecurity: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-27110 being exploited?

CVE-2025-27110 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-27110 affect?

CVE-2025-27110 affects modsecurity. Severity is high (CVSS 7.5). Libmodsecurity is one component of the ModSecurity v3 project. The library codebase serves as an interface to ModSecurity Connectors taking in web traffic and applying traditional ModSecurity processing. A bug that exists only in Libmodsecu

How urgent is CVE-2025-27110?

Priority 47/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-42268 HIGH 7.5 UPGRADE ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx
CVE-2026-52747 HIGH 8.6 UPGRADE ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx
CVE-2026-52761 MEDIUM 5.8 UPGRADE ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx
CVE-2026-30923 HIGH 7.5 UPGRADE ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx
CVE-2025-54571 MEDIUM 6.1 UPGRADE ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx

References

← Back to latest CVEs