CVE-2019-13224: A use-after-free in onig_new_deluxe() in regext.c in Oniguruma 6.9.2 allows attackers to potentially cause inf

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CRITICAL 9.8REMOTEWATCHLISTDOWNGRADEUPGRADEMITIGATE

CVE-2019-13224 is a critical-severity flaw (CVSS 9.8) affecting oniguruma, php, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use-after-free in onig_new_deluxe() in regext.c in Oniguruma 6.9.2 allows attackers to potentially cause information disclosure, denial of service, or possibly code execution by providing a crafted regular expression. The attacker provides a pair of a regex pattern and a string, with a multi-byte encoding that gets handled by onig_new_deluxe(). Oniguruma issues often affect Ruby, as well as common optional libraries for PHP and Rust.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.0% (top 9%)
CISA exploited list	No
Weakness	CWE-416
Published	2019-07-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: canonical · debian · fedoraproject · oniguruma project · php

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

Am I affected?

Timeline

2019-07-10 14:15 UTCPublished CVE record published
2026-06-17 02:16 UTCUpdated Record last modified

oniguruma project oniguruma DOWNGRADE

Affected: 6.9.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.9.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 6.9.2 (Debian / Ubuntu)

apt-cache madison oniguruma sudo apt install oniguruma=<VERSION_BEFORE_6.9.2> sudo apt-mark hold oniguruma

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

dnf --showduplicates list oniguruma sudo dnf downgrade oniguruma-<VERSION_BEFORE_6.9.2> sudo dnf versionlock add oniguruma

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.

php php UPGRADE

Affected: >= 7.1.0 and < 7.1.32 · >= 7.2.0 and < 7.2.23 · >= 7.3.0 and < 7.3.9

Fixed in: 7.1.32, 7.2.23, 7.3.9

Safe to downgrade to: a release before 7.1.0

1. Check installed version

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

2. UPGRADE to 7.1.32 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade php

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade php

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 7.1.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_7.1.0> sudo apt-mark hold php

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

dnf --showduplicates list php sudo dnf downgrade php-<VERSION_BEFORE_7.1.0> sudo dnf versionlock add php

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.

fedoraproject fedora MITIGATE

Affected: 29 · 30

Fixed in: no fixed release known

Safe to downgrade to: a release before 29

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

debian debian linux MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

canonical ubuntu linux MITIGATE

Affected: 12.04 · 14.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2019-13224?

oniguruma: downgrade or apply the listed mitigation; php: upgrade to 7.1.32, 7.2.23, 7.3.9; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-13224 being exploited?

CVE-2019-13224 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-2019-13224 affect?

CVE-2019-13224 affects oniguruma, php, fedora. Severity is critical (CVSS 9.8). A use-after-free in onig_new_deluxe() in regext.c in Oniguruma 6.9.2 allows attackers to potentially cause information disclosure, denial of service, or possibly code execution by providing a crafted regular expression. The attacker provide

How urgent is CVE-2019-13224?

Priority 67/100. Critical severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

PHP vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities · Ruby vulnerabilities

Related CVEs

CVE-2019-19246 HIGH 7.5 UPGRADE UPGRADE Oniguruma through 6.9.3, as used in PHP 7.3.x and other products, has a heap-based buffer over-read in str_low
CVE-2019-19204 HIGH 7.5 UPGRADE MITIGATE An issue was discovered in Oniguruma 6.x before 6.9.4_rc2
CVE-2019-19203 HIGH 7.5 UPGRADE MITIGATE An issue was discovered in Oniguruma 6.x before 6.9.4_rc2
CVE-2019-19012 CRITICAL 9.8 UPGRADE MITIGATE An integer overflow in the search_in_range function in regexec.c in Oniguruma 6.x before 6.9.4_rc2 leads to an
CVE-2019-13225 MEDIUM 6.5 DOWNGRADE MITIGATE A NULL Pointer Dereference in match_at() in regexec.c in Oniguruma 6.9.2 allows attackers to potentially cause

References

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