---
id: "CVE-2026-117500"
kind: "vulnerability"
aliases: ["CVE-2026-117500"]
title: "HTTP::Body (Perl): crafted multipart filename causes CPU exhaustion via regex"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["http-body", "package", "perl", "web-apps"]
not_affected_if: ["no-multipart-uploads", "not-using-http-body"]
published_at: "2026-10-28T18:17:14+00:00"
first_seen_at: "2026-10-28T18:34:33+00:00"
updated_at: "2026-10-28T18:35:18+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117500", "first_seen_at": "2026-10-28T18:34:33+00:00"}]
---

# HTTP::Body (Perl): crafted multipart filename causes CPU exhaustion via regex

HTTP::Body, a Perl module that parses multipart form uploads, runs a regular expression over each uploaded filename that backtracks heavily on filenames made of many dots ending in a backslash. A remote attacker can send one request with a filename of about 32 KB and tie up CPU for several seconds.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `perl -MHTTP::Body -e 'print $HTTP::Body::VERSION'` or `cpanm --info HTTP::Body` to read the installed version
- Check `cpanm --info HTTP::Body` or the lockfile for `HTTP::Body` below `1.24_01`

## Fix

- Upgrade HTTP::Body to `1.24_01` or later, as the fixed release named in the advisory
- Rebuild or redeploy Perl applications after the upgrade so the new module is loaded

## Timeline

- 2026-10-28T18:34:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117500

## From the sources

HTTP::Body versions before 1.24_01 for Perl allow CPU exhaustion via regex backtracking on the filename of a multipart upload.

For every file part, the multipart parser finds the suffix of the uploaded filename by matching the default $basename_regexp, qr/[^.]+(\.[^\\\/]+)$/, against the whole basename. A basename made of many dots and ending in a backslash makes the regex backtrack in time quadratic in its length.

A remote attacker can exhaust CPU with one request, as a basename of about 32 KB takes several seconds to match and every file part is matched separately.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_