CVE-2023-28638: Snappier is a high performance C# implementation of the Snappy compression algorithm

This month

HIGH 7.0REMOTEDOWNGRADE

CVE-2023-28638 is a high-severity flaw (CVSS 7.0) affecting snappier. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Snappier is a high performance C# implementation of the Snappy compression algorithm. This is a buffer overrun vulnerability that can affect any user of Snappier 1.1.0. In this release, much of the code was rewritten to use byte references rather than pointers to pinned buffers. This change generally improves performance and reduces workload on the garbage collector. However, when the garbage collector performs compaction and rearranges memory, i

Why this priority

High severity
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	7.0 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 54%)
CISA exploited list	No
Weakness	CWE-119
Published	2023-03-27
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: snappier project

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

Am I affected?

Timeline

2023-03-27 21:15 UTCPublished CVE record published
2026-06-17 05:48 UTCUpdated Record last modified

snappier project snappier DOWNGRADE

Affected: 1.1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.1.0 (Debian / Ubuntu)

apt-cache madison snappier sudo apt install snappier=<VERSION_BEFORE_1.1.0> sudo apt-mark hold snappier

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

dnf --showduplicates list snappier sudo dnf downgrade snappier-<VERSION_BEFORE_1.1.0> sudo dnf versionlock add snappier

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-2023-28638?

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

Is CVE-2023-28638 being exploited?

CVE-2023-28638 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-2023-28638 affect?

CVE-2023-28638 affects snappier. Severity is high (CVSS 7.0). Snappier is a high performance C# implementation of the Snappy compression algorithm. This is a buffer overrun vulnerability that can affect any user of Snappier 1.1.0. In this release, much of the code was rewritten to use byte references

How urgent is CVE-2023-28638?

Priority 41/100. High severity; Remotely exploitable, no login, no user action

References

← Back to latest CVEs