CVE-2015-2305: Integer overflow in the regcomp implementation in the Henry Spencer BSD regex library (aka rxspencer) alpha3.8

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MEDIUM 6.8WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2015-2305 is a medium-severity flaw (CVSS 6.8) affecting rxspencer, ubuntu linux, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Integer overflow in the regcomp implementation in the Henry Spencer BSD regex library (aka rxspencer) alpha3.8.g5 on 32-bit platforms, as used in NetBSD through 6.1.5 and other products, might allow context-dependent attackers to execute arbitrary code via a large regular expression that leads to a heap-based buffer overflow.

Why this priority

EPSS top 5%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	8.9% (top 5%)
CISA exploited list	No
Weakness	CWE-190
Published	2015-03-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: canonical · debian · opensuse · php · rxspencer project

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

Am I affected?

Timeline

2015-03-30 10:59 UTCPublished CVE record published
2026-06-17 00:23 UTCUpdated Record last modified

rxspencer project rxspencer DOWNGRADE

Affected: 3.8.g5

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.8.g5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.8.g5 (Debian / Ubuntu)

apt-cache madison rxspencer sudo apt install rxspencer=<VERSION_BEFORE_3.8.g5> sudo apt-mark hold rxspencer

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

dnf --showduplicates list rxspencer sudo dnf downgrade rxspencer-<VERSION_BEFORE_3.8.g5> sudo dnf versionlock add rxspencer

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.

canonical ubuntu linux MITIGATE

Affected: 10.04 · 12.04 · 14.04 · 14.10 · 15.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.04

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.

debian debian linux MITIGATE

Affected: 7.0 · 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

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.

opensuse opensuse MITIGATE

Affected: 13.1 · 13.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 13.1

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.

php php UPGRADE

Affected: >= 5.4.0 and < 5.4.39 · >= 5.5.0 and < 5.5.23 · >= 5.6.0 and < 5.6.7

Fixed in: 5.4.39, 5.5.23, 5.6.7

Safe to downgrade to: a release before 5.4.0

1. Check installed version

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

2. UPGRADE to 5.4.39 (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 5.4.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_5.4.0> 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_5.4.0> 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.

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-2015-2305?

rxspencer: downgrade or apply the listed mitigation; ubuntu linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2015-2305 being exploited?

CVE-2015-2305 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-2015-2305 affect?

CVE-2015-2305 affects rxspencer, ubuntu linux, debian linux. Severity is medium (CVSS 6.8). Integer overflow in the regcomp implementation in the Henry Spencer BSD regex library (aka rxspencer) alpha3.8.g5 on 32-bit platforms, as used in NetBSD through 6.1.5 and other products, might allow context-dependent attackers to execute ar

How urgent is CVE-2015-2305?

Priority 58/100. EPSS top 5%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

PHP vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

References

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