CVE-2019-11387: An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0

This month

MEDIUM 5.3REMOTEUPGRADE

CVE-2019-11387 is a medium-severity flaw (CVSS 5.3) affecting owasp modsecurity core rule set. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-942-APPLICATION-ATTACK-SQLI.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with nested repetition operators.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-400
Published	2019-04-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: modsecurity

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

Am I affected?

Timeline

2019-04-21 02:29 UTCPublished CVE record published
2026-06-17 02:12 UTCUpdated Record last modified

modsecurity owasp modsecurity core rule set UPGRADE

Affected: >= 3.0.0 and <= 3.1.0

Fixed in: newer than 3.1.0

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy owasp-modsecurity-core-rule-set || rpm -q owasp-modsecurity-core-rule-set || owasp-modsecurity-core-rule-set --version

2. UPGRADE to newer than 3.1.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade owasp-modsecurity-core-rule-set

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade owasp-modsecurity-core-rule-set

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison owasp-modsecurity-core-rule-set sudo apt install owasp-modsecurity-core-rule-set=<VERSION_BEFORE_3.0.0> sudo apt-mark hold owasp-modsecurity-core-rule-set

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list owasp-modsecurity-core-rule-set sudo dnf downgrade owasp-modsecurity-core-rule-set-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add owasp-modsecurity-core-rule-set

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-2019-11387?

owasp modsecurity core rule set: upgrade to newer than 3.1.0. Exact commands for each OS are on this page.

Is CVE-2019-11387 being exploited?

CVE-2019-11387 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-2019-11387 affect?

CVE-2019-11387 affects owasp modsecurity core rule set. Severity is medium (CVSS 5.3). An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-942-APPLICATION-ATTACK-SQLI.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with nested

How urgent is CVE-2019-11387?

Priority 45/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-33691 MEDIUM 6.8 UPGRADE The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web applicati
CVE-2026-21876 CRITICAL 9.3 UPGRADE The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web applicati
CVE-2022-39958 HIGH 7.5 UPGRADE MITIGATE The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass to sequentially exfiltrate sma
CVE-2022-39957 HIGH 7.3 UPGRADE MITIGATE The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass
CVE-2022-39956 HIGH 7.3 UPGRADE MITIGATE The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass for HTTP multipart requests

References

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