CVE-2026-27171

low-risk
Published 2026-02-18

zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.

Do I need to act?

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0.01% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
2
CVSS 2.9/10 Low
LOCAL / HIGH complexity

Affected Products (1)

Affected Vendors

Zlib

References (6)

Product https://7asecurity.com/blog/2026/02/zlib-7asecurity-audit/
Technical Description https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf
Exploit https://github.com/madler/zlib/issues/904
Release Notes https://github.com/madler/zlib/releases/tag/v1.3.2
Product https://ostif.org/zlib-audit-complete/
Technical Description https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf
13
/ 100
low-risk
Severity 8/34 · Low
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal