CVE-2026-91018

HIGH 8.8

Double Free in lwIP (lightweight IP)

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

lwIP (Lightweight IP) has a double free vulnerability, which could crash the system, cause a DoS, memory corruption, or allow code execution on the victim system.

CWE	CWE-415
Vendor	lwip
Product	lwip api
Published	Sep 22, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

lwIP / lwIP API

2.0.1 ≤ 2.2.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

cgit.git.savannah.gnu.org: https://cgit.git.savannah.gnu.org/cgit/lwip.git cisa.gov: https://www.cisa.gov/news-events/ics-advisories/icsa-26-265-02 github.com: https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-265-02.json

Credits

Eric Evenchick of Tetrel Security reported this vulnerability to CISA.