CVE-2023-22796: A regular expression based DoS vulnerability in Active Support <6.1.7.1 and <7.0.4.1

Q: How do I fix CVE-2023-22796?

activesupport: upgrade to 6.1.7.1, 7.0.4.1. Exact commands for each OS are on this page.

Q: Is CVE-2023-22796 being exploited?

CVE-2023-22796 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-22796 affect?

CVE-2023-22796 affects activesupport. Severity is high (CVSS 7.5). A regular expression based DoS vulnerability in Active Support <6.1.7.1 and <7.0.4.1. A specially crafted string passed to the underscore method can cause the regular expression engine to enter a state of catastrophic backtracking. This can

Q: How urgent is CVE-2023-22796?

Priority 51/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2023-22796 is a high-severity flaw (CVSS 7.5) affecting activesupport. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A regular expression based DoS vulnerability in Active Support <6.1.7.1 and <7.0.4.1. A specially crafted string passed to the underscore method can cause the regular expression engine to enter a state of catastrophic backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-400, CWE-1333
Published	2023-02-09
Last modified	2026-10-24

Publisher (CNA): HackerOne · Vendor: activesupport project

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-02-09 20:15 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

activesupport project activesupport UPGRADE

Affected: < 6.1.7.1 · >= 7.0.0 and < 7.0.4.1

Fixed in: 6.1.7.1, 7.0.4.1

Safe to downgrade to: a release before 7.0.0

1. Check installed version

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

2. UPGRADE to 6.1.7.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade activesupport

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 7.0.0 (Debian / Ubuntu)

apt-cache madison activesupport sudo apt install activesupport=<VERSION_BEFORE_7.0.0> sudo apt-mark hold activesupport

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

dnf --showduplicates list activesupport sudo dnf downgrade activesupport-<VERSION_BEFORE_7.0.0> sudo dnf versionlock add activesupport

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.

Exact fixes by distribution

RubyGems · activesupport · FIXED · 7.0.4.1 · vulnerable: >= 7.0.0, < 7.0.4.1 · source

bundle update activesupport bundle list | grep activesupport

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Debian 12 · rails · FIXED · 2:6.1.7.3+dfsg-1

sudo apt update && sudo apt install --only-upgrade rails dpkg --compare-versions "$(dpkg-query -W -f='${Version}' rails)" ge "2:6.1.7.3+dfsg-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · rails · FIXED · 2:6.1.7.3+dfsg-1

sudo apt update && sudo apt install --only-upgrade rails dpkg --compare-versions "$(dpkg-query -W -f='${Version}' rails)" ge "2:6.1.7.3+dfsg-1" && echo PATCHED || echo STILL-VULNERABLE

Alpine 3.20 · ruby-activesupport · FIXED · ruby-activesupport-7.0.4.3-r0

apk add --upgrade ruby-activesupport apk info -v ruby-activesupport

Alpine 3.21 · ruby-activesupport · FIXED · ruby-activesupport-7.0.4.3-r0

apk add --upgrade ruby-activesupport apk info -v ruby-activesupport

Alpine 3.22 · ruby-activesupport · FIXED · ruby-activesupport-7.0.4.3-r0

apk add --upgrade ruby-activesupport apk info -v ruby-activesupport

Alpine 3.23 · ruby-activesupport · FIXED · ruby-activesupport-7.0.4.3-r0

apk add --upgrade ruby-activesupport apk info -v ruby-activesupport

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-2023-22796?

activesupport: upgrade to 6.1.7.1, 7.0.4.1. Exact commands for each OS are on this page.

Is CVE-2023-22796 being exploited?

CVE-2023-22796 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-2023-22796 affect?

CVE-2023-22796 affects activesupport. Severity is high (CVSS 7.5). A regular expression based DoS vulnerability in Active Support <6.1.7.1 and <7.0.4.1. A specially crafted string passed to the underscore method can cause the regular expression engine to enter a state of catastrophic backtracking. This can

How urgent is CVE-2023-22796?

Priority 51/100. High severity; Remotely exploitable, no login, no user action

References

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