CVE-2026-89157: PCRE2 before 10.48, on 32-bit platforms, has a pcre2_pattern_convert out-of-bounds write when an attacker can

Routine

MEDIUM 5.7UPGRADE

CVE-2026-89157 is a medium-severity flaw (CVSS 5.7) affecting pcre2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PCRE2 before 10.48, on 32-bit platforms, has a pcre2_pattern_convert out-of-bounds write when an attacker can provide a large pattern.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.7 (Medium)
Attack vector	Local
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 72%)
CISA exploited list	No
Weakness	CWE-190
Published	2026-09-11
Last modified	2026-09-16

Publisher (CNA): MITRE · Vendor: pcre

Last updated 2026-09-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-11 04:18 UTCPublished CVE record published
2026-09-16 19:25 UTCUpdated Record last modified

pcre pcre2 UPGRADE

Affected: >= 10.30 and < 10.48 · 10.48 rc1

Fixed in: 10.48

Safe to downgrade to: a release before 10.30

1. Check installed version

apt-cache policy pcre2 || rpm -q pcre2 || pcre2 --version

2. UPGRADE to 10.48 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pcre2

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pcre2

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 10.30 (Debian / Ubuntu)

apt-cache madison pcre2 sudo apt install pcre2=<VERSION_BEFORE_10.30> sudo apt-mark hold pcre2

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

dnf --showduplicates list pcre2 sudo dnf downgrade pcre2-<VERSION_BEFORE_10.30> sudo dnf versionlock add pcre2

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-2026-89157?

pcre2: upgrade to 10.48. Exact commands for each OS are on this page.

Is CVE-2026-89157 being exploited?

CVE-2026-89157 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-2026-89157 affect?

CVE-2026-89157 affects pcre2. Severity is medium (CVSS 5.7). PCRE2 before 10.48, on 32-bit platforms, has a pcre2_pattern_convert out-of-bounds write when an attacker can provide a large pattern.

How urgent is CVE-2026-89157?

Priority 32/100. Public exploit reference

Related CVEs

CVE-2026-89156 LOW 2.9 UPGRADE PCRE2 before 10.48 has a pcre2_match out-of-bounds read after a JIT fallback when an attacker can provide inva
CVE-2026-89158 MEDIUM 6.5 UPGRADE PCRE2 before 10.48, on 32-bit platforms, has a pcre2_compile_32 integer overflow and resultant out-of-bounds w
CVE-2026-89160 LOW 3.7 UPGRADE PCRE2 before 10.48 has a pcre2_match out-of-bounds read during the PCRE2_MATCH_INVALID_UTF matching of an inva
CVE-2026-89161 HIGH 7.4 UPGRADE In PCRE2 before 10.48, pcre2_jit_match mishandles a previously copied subject being passed in as a context
CVE-2026-89162 LOW 2.9 UPGRADE In PCRE2 before 10.48, pcre2_serialize_encode might disclose two bytes to an adversary, typically in a situati

References

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