CVE-2022-28739: There is a buffer over-read in Ruby before 2.6.10, 2.7.x before 2.7.6, 3.x before 3.0.4, and 3.1.x before 3.1.

Q: How do I fix CVE-2022-28739?

ruby: upgrade to 2.6.10, 2.7.6, 3.0.4, 3.1.2; debian linux: mitigate or apply the listed mitigation; macos: upgrade to 11.7.1, 12.6.1. Exact commands for each OS are on this page.

Q: Is CVE-2022-28739 being exploited?

CVE-2022-28739 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-2022-28739 affect?

CVE-2022-28739 affects ruby, debian linux, macos. Severity is high (CVSS 7.5). There is a buffer over-read in Ruby before 2.6.10, 2.7.x before 2.7.6, 3.x before 3.0.4, and 3.1.x before 3.1.2. It occurs in String-to-Float conversion, including Kernel#Float and String#to_f.

Q: How urgent is CVE-2022-28739?

Priority 59/100. High severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This month

HIGH 7.5REMOTEWATCHLISTUPGRADEMITIGATEUPGRADE

CVE-2022-28739 is a high-severity flaw (CVSS 7.5) affecting ruby, debian linux, macos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

There is a buffer over-read in Ruby before 2.6.10, 2.7.x before 2.7.6, 3.x before 3.0.4, and 3.1.x before 3.1.2. It occurs in String-to-Float conversion, including Kernel#Float and String#to_f.

Why this priority

High 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	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.4% (top 9%)
CISA exploited list	No
Weakness	CWE-125
Published	2022-05-09
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: apple · debian · ruby-lang

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

Am I affected?

Timeline

2022-05-09 18:15 UTCPublished CVE record published
2026-06-17 04:38 UTCUpdated Record last modified

ruby-lang ruby UPGRADE

Affected: < 2.6.10 · >= 2.7.0 and < 2.7.6 · >= 3.0.0 and < 3.0.4 · >= 3.1.0 and < 3.1.2

Fixed in: 2.6.10, 2.7.6, 3.0.4, 3.1.2

Safe to downgrade to: a release before 2.7.0

1. Check installed version

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

2. UPGRADE to 2.6.10 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ruby

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 2.7.0 (Debian / Ubuntu)

apt-cache madison ruby sudo apt install ruby=<VERSION_BEFORE_2.7.0> sudo apt-mark hold ruby

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

dnf --showduplicates list ruby sudo dnf downgrade ruby-<VERSION_BEFORE_2.7.0> sudo dnf versionlock add ruby

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.

debian debian linux MITIGATE

Affected: 9.0 · 10.0 · 11.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

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.

apple macos UPGRADE

Affected: >= 11.0 and < 11.7.1 · >= 12.0 and < 12.6.1

Fixed in: 11.7.1, 12.6.1

Safe to downgrade to: a release before 11.0

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.

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-2022-28739?

ruby: upgrade to 2.6.10, 2.7.6, 3.0.4, 3.1.2; debian linux: mitigate or apply the listed mitigation; macos: upgrade to 11.7.1, 12.6.1. Exact commands for each OS are on this page.

Is CVE-2022-28739 being exploited?

CVE-2022-28739 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-2022-28739 affect?

CVE-2022-28739 affects ruby, debian linux, macos. Severity is high (CVSS 7.5). There is a buffer over-read in Ruby before 2.6.10, 2.7.x before 2.7.6, 3.x before 3.0.4, and 3.1.x before 3.1.2. It occurs in String-to-Float conversion, including Kernel#Float and String#to_f.

How urgent is CVE-2022-28739?

Priority 59/100. High severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · macOS vulnerabilities · Ruby vulnerabilities

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References

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