CVE-2020-22916: An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafted f

Routine

MEDIUM 5.5DOWNGRADE

CVE-2020-22916 is a medium-severity flaw (CVSS 5.5) affecting xz. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafted file. NOTE: the vendor disputes the claims of "endless output" and "denial of service" because decompression of the 17,486 bytes always results in 114,881,179 bytes, which is often a reasonable size increase.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Published	2023-08-22
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: tukaani

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

Am I affected?

Timeline

2023-08-22 19:16 UTCPublished CVE record published
2026-06-17 03:04 UTCUpdated Record last modified

tukaani xz DOWNGRADE

Affected: 5.2.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.2.5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 5.2.5 (Debian / Ubuntu)

apt-cache madison xz sudo apt install xz=<VERSION_BEFORE_5.2.5> sudo apt-mark hold xz

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

dnf --showduplicates list xz sudo dnf downgrade xz-<VERSION_BEFORE_5.2.5> sudo dnf versionlock add xz

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-2020-22916?

xz: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-22916 being exploited?

CVE-2020-22916 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-2020-22916 affect?

CVE-2020-22916 affects xz. Severity is medium (CVSS 5.5). An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafted file. NOTE: the vendor disputes the claims of "endless output" and "denial of service" because decompression of the 17,486 bytes al

How urgent is CVE-2020-22916?

Priority 23/100. No elevated risk signals yet.

Related CVEs

CVE-2022-1271 HIGH 8.8 UPGRADE DOWNGRADE An arbitrary file write vulnerability was found in GNU gzip's zgrep utility
CVE-2026-34743 MEDIUM 5.3 UPGRADE XZ Utils provide a general-purpose data-compression library plus command-line tools
CVE-2024-3094 CRITICAL 10.0 DOWNGRADE Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0
CVE-2021-29482 HIGH 7.5 UPGRADE xz is a compression and decompression library focusing on the xz format completely written in Go
CVE-2015-4035 HIGH 7.8 UPGRADE scripts/xzgrep.in in xzgrep 5.2.x before 5.2.0, before 5.0.0 does not properly process file names containing s

References

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