---
id: CVE-2026-115822
title: >-
  Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic
  regex backtracking when parsing chunked request bodies
summary: >-
  Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic
  regex backtracking when parsing chunked request bodies.


  Starman decodes chunked request bodies before calling the application,
  matching each chunk-size line with…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: adp
cwe:
  - CWE-1333
product: Starman
affected:
  - Starman < 0.4019
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-11-02T14:19:14.376911Z'
published: '2026-10-25'
updated: '2026-11-02'
sourceUpdated: '2026-11-02T14:19:20.636Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115822'
references:
  - url: >-
      https://github.com/miyagawa/Starman/commit/0f33f9b132b5e410d6cce722ff71988e22476acf.patch
  - url: 'https://metacpan.org/release/MIYAGAWA/Starman-0.4019/changes'
tags:
  - cve.org
epss: 0.00506
epssPercentile: 0.4335
ingestedAt: '2026-10-25T22:08:29.931Z'
---

## Overview

Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies.

Starman decodes chunked request bodies before calling the application, matching each chunk-size line with `s/^(([0-9a-fA-F]+).*\015\012)//`. A line of hex digits followed by a bare LF and then CRLF never matches, because `.` does not match LF, and each failed attempt backtracks in time quadratic in the length of the hex run. Nothing limits the length of the line.

A remote attacker can exhaust worker CPU by sending such requests to any route.

## Affected

- `Starman < 0.4019`

## Remediation

Upgrade to Starman 0.4019 or later.