Vulnerability Report

CVE-2026-27171

Title: CPU consumption via crc32_combine64 in zlib

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-27171.

CWE Category CWE-1284
Published Date Feb 18, 2026
Modified Date Mar 25, 2026
Exploit Status Not Found
Score 2.9 CVSS v3.1
Exploit Probability (EPSS)
0.01%

Vulnerability Summary

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.

Impacted Vendors

Z
zlib 1
C
cloudflare 1

Reference Links

https://7asecurity.com/blog/2026/02/zlib-7asecurity-audit/ https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf https://github.com/madler/zlib/issues/904 https://github.com/madler/zlib/releases/tag/v1.3.2 https://ostif.org/zlib-audit-complete/
CVSS v3.1
Source Entity [email protected]
Severity LOW
2.9
Attack Vector
LOCAL
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.5
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-27171 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector LOCAL
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Stack

No specific products linked.