CVE-2020-22916
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA crafted XZ-compressed file of 17,486 bytes decompresses to approximately 114.9 million bytes, representing an extreme expansion ratio of roughly 6,500x. When decompressed, this can cause excessive memory or disk consumption leading to denial of service through resource exhaustion.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 5.2.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check if XZ tools are installedRun 'which xz' or check your package manager for the xz or xz-utils packageAffected if No XZ tools are found (not vulnerable as the tool is not present)
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Identify the installed XZ versionRun 'xz --version' to obtain the version numberAffected if The version displayed is 5.2.5 (the only version listed as affected)
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Determine if untrusted XZ files are processedReview any scripts, applications, or workflows that decompress XZ files, particularly from external or untrusted sourcesAffected if The environment decompresses XZ files from untrusted or external sources without resource limits
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Check for decompression resource limitsInspect application logic or system configurations (such as ulimit, container memory limits, or application-specific sandboxing) that restrict memory or disk usage during decompressionAffected if No resource limits are configured and untrusted XZ files are being processed
You are affected if XZ version 5.2.5 is installed AND you decompress XZ files from untrusted sources without resource limits in place.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedImplement resource limits (memory/disk) when decompressing untrusted XZ files, or avoid decompressing files from untrusted sources. Consider upgrading to a patched version of XZ if one becomes available.
Any stable release newer than 5.2.5 (e.g., 5.4.x series)
- 1. Check current XZ version by running: xz --version
- 2. Download the latest stable XZ release from https://tukaani.org/xz/ or use your system's package manager
- 3. For source compilation: download xz-5.4.x, extract, run ./configure, make, make install
- 4. Or via package manager: apt-get install xz-utils (Debian/Ubuntu), yum install xz (RHEL/CentOS), zypper install xz (SUSE)
- 5. Verify the new version: xz --version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-22916 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-22916 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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