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Vulnerabilities

Vulnerability · CVE-2025-11677

Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callb

Published Oct 20, 2025 · catalog updated Oct 24, 2025 · Use After Free in

Last checked Oct 26, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-11677. EPSS is 0.40%. Act only if a listed version of Use After Free in is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Use After Free in).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.40%
Remediation
Vendor / distro source
Affected products
vendor warmcat libwebsockets 3 ≤4.4.1,4.3.6

Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor warmcat libwebsockets 3 ≤4.4.1,4.3.63 ≤4.4.1,4.3.6

How to fix CVE-2025-11677

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-11677. EPSS is 0.40%. Act only if a listed version of Use After Free in is installed.

Which versions are affected?

Compare what you have installed with warmcat libwebsockets 3 ≤4.4.1,4.3.6 3 ≤4.4.1,4.3.6. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.40%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 20, 2025 · EUVD

    Detected

    Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

  2. Oct 24, 2025 · EUVD

    Updated

    Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

Sources

  • CVE.orgVulnerability recordCVE-2025-11677

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-11677

    30-day exploitation probability 0.40%

    first.org
  • EUVDVulnerability recordEUVD-2025-35045

    Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 26, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 26, 2026
  • CVE.orgOct 26, 2026
  • EUVDOct 26, 2026