CVE-2022-4904: A flaw was found in the c-ares package

Q: How do I fix CVE-2022-4904?

c-ares: upgrade to 1.19.0; software collections: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2022-4904 being exploited?

CVE-2022-4904 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-2022-4904 affect?

CVE-2022-4904 affects c-ares, software collections, enterprise linux. Severity is high (CVSS 8.6). A flaw was found in the c-ares package. The ares_set_sortlist is missing checks about the validity of the input string, which allows a possible arbitrary length stack overflow. This issue may cause a denial of service or a limited impact on

Q: How urgent is CVE-2022-4904?

Priority 62/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

This week

HIGH 8.6REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2022-4904 is a high-severity flaw (CVSS 8.6) affecting c-ares, software collections, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in the c-ares package. The ares_set_sortlist is missing checks about the validity of the input string, which allows a possible arbitrary length stack overflow. This issue may cause a denial of service or a limited impact on confidentiality and integrity.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.6 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-20, CWE-1284
Published	2023-03-06
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: c-ares project · fedoraproject · redhat

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

Am I affected?

Timeline

2023-03-06 23:15 UTCPublished CVE record published
2026-06-17 05:22 UTCUpdated Record last modified

c-ares project c-ares UPGRADE

Affected: < 1.19.0

Fixed in: 1.19.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy c-ares || rpm -q c-ares || c-ares --version

2. UPGRADE to 1.19.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade c-ares

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade c-ares

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

redhat software collections MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy software-collections || rpm -q software-collections || software-collections --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

redhat enterprise linux MITIGATE

Affected: 8.0 · 9.0

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.

fedoraproject fedora MITIGATE

Affected: 36

Fixed in: no fixed release known

Safe to downgrade to: a release before 36

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.

Advisories and coverage

Official advisories

Ubuntu Security Notices: USN-8951-1: c-ares vulnerabilities 2026-10-21

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-2022-4904?

c-ares: upgrade to 1.19.0; software collections: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-4904 being exploited?

CVE-2022-4904 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-2022-4904 affect?

CVE-2022-4904 affects c-ares, software collections, enterprise linux. Severity is high (CVSS 8.6). A flaw was found in the c-ares package. The ares_set_sortlist is missing checks about the validity of the input string, which allows a possible arbitrary length stack overflow. This issue may cause a denial of service or a limited impact on

How urgent is CVE-2022-4904?

Priority 62/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2025-62408 MEDIUM 5.9 UPGRADE c-ares is an asynchronous resolver library
CVE-2024-25629 MEDIUM 4.4 UPGRADE MITIGATE c-ares is a C library for asynchronous DNS requests
CVE-2023-32067 HIGH 7.5 UPGRADE MITIGATE c-ares is an asynchronous resolver library
CVE-2023-31147 MEDIUM 5.9 UPGRADE MITIGATE c-ares is an asynchronous resolver library
CVE-2023-31130 MEDIUM 4.1 UPGRADE MITIGATE c-ares is an asynchronous resolver library

References

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