How severe is CVE-2022-4899?

CVE-2022-4899 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-4899?

CVE-2022-4899 affects the following packages: zstd (PyPI), github.com/facebook/zstd (SwiftURL). Ecosystems affected: PyPI, SwiftURL.

How do I fix CVE-2022-4899?

Update zstd to 1.5.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-4899 is resolved across your whole dependency graph.

How do I detect CVE-2022-4899 in my PyPI, SwiftURL dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zstd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-4899 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2022-4899 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-4899 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2022-4899?

CVE-2022-4899 has an EPSS (Exploit Prediction Scoring System) score of 1.6%, placing it in the 76th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2022-4899?

CVE-2022-4899 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-4899 published, and has it been updated?

CVE-2022-4899 was published on March 31, 2023 and was last updated on October 31, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI📦 SwiftURL

Not in CISA KEV

HIGH severity

CVE-2022-4899 — zstd

HIGHFix: facebook/zstd#3220

CVE-2022-4899 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in zstd. A fix is available for zstd — see the affected versions and patch details below.

zstd vulnerable to buffer overrun

Also known asGHSA-5c9c-6x87-f9vm

Published

Mar 31, 2023

Updated

Oct 31, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2022-4899.

EPSS Exploitation Probability

via FIRST.org ↗

1.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs76th percentile — riskier than 76% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐍zstd📦github.com/facebook/zstd

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI, SwiftURL packages — download data is not available via public APIs for these ecosystems.

Description

A vulnerability was found in zstd v1.4.10, where an attacker can supply an empty string as an argument to the command line tool to cause buffer overrun.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`zstd`	all versions	1.5.4.0`pip install --upgrade 'zstd==1.5.4.0'`
📦SwiftURL	`github.com/facebook/zstd`	all versions	1.5.4

Affected Products

1 product · 1 configurations

Application

zstandardfacebook

1 version

1.4.10

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zstd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zstd to 1.5.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-4899 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

The vulnerability in the zstd command-line utility is rated as Moderate Severity because it involves an Incorrect Calculation of Buffer Size (CWE-400) within the mallocAndJoin2Dir function in programs/util.c. A remote attacker can exploit this flaw by providing an input, specifically an empty string, which causes a…

Product	Fixed in	Advisory
Red Hat AMQ Streams 2.7.0	see advisory	RHSA-2024:3527
Red Hat Enterprise Linux 8	`mysql:8.0-8090020240126173013.a75119d5`	RHSA-2024:0894
Red Hat Enterprise Linux 9	`mysql-0:8.0.36-1.el9_3`	RHSA-2024:1141
Red Hat Software Collections for Red Hat Enterprise Linux 7	`rh-mysql80-mysql-0:8.0.36-1.el7`	RHSA-2024:2619

Frequently Asked Questions