CVE-2026-27171: Medium severity zlib vulnerability

Published Feb 18, 2026
·
Updated

zlib before 1.3.2 allows CPU consumption via crc32combine64 and crc32combinegen64 because x2nmodp can do right shifts within a loop that has no termination condition.

Affected Software

3 affected componentsFixes available
zlib<1.3.2
Microsoft azl3 zlib 1.3.1-1
zlib zlib>=1.2.12<1.3.2

Event History

Feb 18, 2026
CVE Published
via MITRE·02:36 AM
Data Sourced
via MITRE·02:36 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:16 AM
DescriptionSeverityWeaknessAffected Software
Feb 21, 2026
Data Sourced
via Microsoft·12:27 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·12:27 PM
DescriptionSeverity
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Frequently Asked Questions

1

What is the severity of CVE-2026-27171?

CVE-2026-27171 is classified with a high severity due to its potential to cause significant CPU consumption.

2

How do I fix CVE-2026-27171?

To fix CVE-2026-27171, you should upgrade to zlib version 1.3.2 or later.

3

What systems are affected by CVE-2026-27171?

CVE-2026-27171 affects all versions of zlib prior to version 1.3.2.

4

What type of vulnerability is CVE-2026-27171?

CVE-2026-27171 is a denial-of-service vulnerability that can lead to excessive CPU usage.

5

Is there a workaround for CVE-2026-27171?

There are no known effective workarounds for CVE-2026-27171, and updating zlib is recommended.

Contact

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