CVE-2026-22184: zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under

Q: How do I fix CVE-2026-22184?

zlib: upgrade to newer than 1.3.1.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-22184 being exploited?

CVE-2026-22184 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-2026-22184 affect?

CVE-2026-22184 affects zlib. Severity is high (CVSS 7.8). zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression

Routine

HIGH 7.8UPGRADE

CVE-2026-22184 is a high-severity flaw (CVSS 7.8) affecting zlib. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression library. The flaw occurs when a user executes the untgz command with an excessively long archive name supplied via the command line, leading to an out-of-bounds write in a fixed-size global buffer.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-787, CWE-120
Published	2026-01-07
Last modified	2026-09-01

Publisher (CNA): VulnCheck · Vendor: zlib

Last updated 2026-09-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-07 21:16 UTCPublished CVE record published
2026-09-01 13:18 UTCUpdated Record last modified

zlib zlib UPGRADE

Affected: <= 1.3.1.2

Fixed in: newer than 1.3.1.2

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 1.3.1.2 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade zlib

Note

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

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-2026-22184?

zlib: upgrade to newer than 1.3.1.2. Exact commands for each OS are on this page.

Is CVE-2026-22184 being exploited?

CVE-2026-22184 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-2026-22184 affect?

CVE-2026-22184 affects zlib. Severity is high (CVSS 7.8). zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression

How urgent is CVE-2026-22184?

Priority 36/100. High severity

Software pages

zlib vulnerabilities

Related CVEs

CVE-2026-27820 CRITICAL 9.8 UPGRADE zlib is a Ruby interface for the zlib compression/decompression library
CVE-2026-27171 LOW 2.9 UPGRADE zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do ri

References

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