CVE-2026-56853 — HIGH (7.5)

Vulnerability Description

When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.

CVSS Score

7.5

HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Related Weaknesses (CWE)

CWE-770

References

FAQ

What is CVE-2026-56853?

CVE-2026-56853 is a vulnerability with a CVSS score of 7.5 (HIGH). When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being a...

How severe is CVE-2026-56853?

CVE-2026-56853 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-56853?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.