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CVE-2026-271357.5HighCWE-617

CVE-2026-27135: nghttp2 Denial of service: Assertion failure due to the missing state validation

nghttp2

Vendor fix available · Affected: nghttp2 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.9%probability of exploitation in the next 30 days
59th percentile
050100

Higher than 59% of scored CVEs

7.5HighCVSS 3.1
LowHigh

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

  • nghttp2 · nghttp2< 1.68.1

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

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Exploitation
Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV
Not listed
Public check
No public nuclei template
Vendor
nghttp2
Published
March 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-27135 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

28 more references are in the CVE record.