CVE-2021-32840: SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library

Q: How do I fix CVE-2021-32840?

sharpziplib: upgrade to 1.3.3. Exact commands for each OS are on this page.

Q: Is CVE-2021-32840 being exploited?

CVE-2021-32840 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-2021-32840 affect?

CVE-2021-32840 affects sharpziplib. Severity is high (CVSS 7.3). SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Prior to version 1.3.3, a TAR file entry `../evil.txt` may be extracted in the parent directory of `destFolder`. This leads to arbitrary file write that may lead to code execut

Q: How urgent is CVE-2021-32840?

Priority 50/100. High severity; Public exploit reference

This month

HIGH 7.3UPGRADE

CVE-2021-32840 is a high-severity flaw (CVSS 7.3) affecting sharpziplib. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Prior to version 1.3.3, a TAR file entry `../evil.txt` may be extracted in the parent directory of `destFolder`. This leads to arbitrary file write that may lead to code execution. The vulnerability was patched in version 1.3.3.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.3 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.9% (top 20%)
CISA exploited list	No
Weakness	CWE-22
Published	2022-01-26
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2022-01-26 21:15 UTCPublished CVE record published
2026-06-17 03:53 UTCUpdated Record last modified

sharpziplib project sharpziplib UPGRADE

Affected: < 1.3.3

Fixed in: 1.3.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.3.3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sharpziplib

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-2021-32840?

sharpziplib: upgrade to 1.3.3. Exact commands for each OS are on this page.

Is CVE-2021-32840 being exploited?

CVE-2021-32840 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-2021-32840 affect?

CVE-2021-32840 affects sharpziplib. Severity is high (CVSS 7.3). SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Prior to version 1.3.3, a TAR file entry `../evil.txt` may be extracted in the parent directory of `destFolder`. This leads to arbitrary file write that may lead to code execut

How urgent is CVE-2021-32840?

Priority 50/100. High severity; Public exploit reference

Related CVEs

CVE-2021-32842 MEDIUM 4.0 UPGRADE SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library
CVE-2021-32841 MEDIUM 4.0 UPGRADE SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library

References

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