CVE-2026-27135

Advisory lineage Upstream: 0 Downstream: 50
Modified
Published: 18 Mar 2026, 17:59
Last modified:15 Jul 2026, 01:14

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.78% LOW
1% probability +0.21%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

18 Mar 2026, 17:59
Published
Vulnerability first disclosed
15 Jul 2026, 01:14
Last Modified
Vulnerability information updated

Description

nghttp2 is an implementation of the Hypertext Transfer Protocol version 2 in C. Prior to version 1.68.1, the nghttp2 library stops reading the incoming data when user facing public API `nghttp2_session_terminate_session` or `nghttp2_session_terminate_session2` is called by the application. They might be called internally by the library when it detects the situation that is subject to connection error. Due to the missing internal state validation, the library keeps reading the rest of the data after one of those APIs is called. Then receiving a malformed frame that causes FRAME_SIZE_ERROR causes assertion failure. nghttp2 v1.68.1 adds missing state validation to avoid assertion failure. No known workarounds are available.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.78%• Percentile: 51%

Techniques & Countermeasures

  • CWE-617•Reachable Assertion

    The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

Affected Systems

  • nghttp2•nghttp2

    < 1.68.1

References (55)