CVE-2026-115822

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

Published Oct 25, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Upgrade to Starman 0.4019 or later.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Miyagawa
Miyagawa starman
Vendors & Products Miyagawa
Miyagawa starman
Type Values Removed Values Added
Description 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.
Title Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies
Weaknesses CWE-1333
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Nov 2, 2026, 2:19 PM
Reserved
Oct 23, 2026, 4:47 PM
Status
Deferred
Published
Oct 25, 2026, 5:17 PM
Modified
Nov 2, 2026, 3:17 PM