Double Free Vulnerability in lwIP Affects GNU
CVE-2026-91018

8.7HIGH

Key Information:

Vendor

Lwip

Status
Lwip Api
Vendor
CVE Published:
22 September 2026

What is CVE-2026-91018?

The lwIP (Lightweight IP) library is affected by a double free vulnerability, which can lead to critical system failures. This flaw may enable an attacker to exploit the memory management of the lwIP framework, resulting in potential system crashes, denial of service (DoS), or even arbitrary code execution. Proper mitigation measures should be employed to protect systems utilizing lwIP, thereby preventing exploitation of this vulnerability.

Affected Version(s)

lwIP API 2.0.1 <= 2.2.1

References

https://cgit.git.savannah.gnu.org/cgit/lwip.git
https://www.cisa.gov/news-events/ics-advisories/icsa-26-2...
https://github.com/cisagov/CSAF/blob/develop/csaf_files/O...

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Eric Evenchick of Tetrel Security reported this vulnerability to CISA.
.