How severe is CVE-2026-27171?

CVE-2026-27171 has a CVSS 3.x base score of 2.9, rated low severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-27171 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27171?

CVE-2026-27171 affects Zlib. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27171?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-27171 have an EU (EUVD) identifier?

Yes. CVE-2026-27171 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8063.

When was CVE-2026-27171 published?

CVE-2026-27171 was published on 2026-02-18 and last updated on 2026-06-17.

CVE-2026-27171

CVE-2026-27171 is a low-severity vulnerability in Zlib with a CVSS 3.x base score of 2.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1284.

Key facts

Severity: Low (CVSS 3.x base score 2.9)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8063
Weakness: CWE-1284
Affected product: Zlib
Published: 2026-02-18
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-27171?: 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.
How severe is CVE-2026-27171?: CVE-2026-27171 has a CVSS 3.x base score of 2.9, rated low severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-27171 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27171?: CVE-2026-27171 affects Zlib. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27171?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-27171 have an EU (EUVD) identifier?: Yes. CVE-2026-27171 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8063.
When was CVE-2026-27171 published?: CVE-2026-27171 was published on 2026-02-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:zlib:zlib:*:*:*:*:*:*:*:*

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