CVE-2026-115822VulnerabilityPublished 25 Oct 2026

CVE-2026-115822: Starman (Perl module) · ReDoS

Affects Starman (Perl module)Source CVE Database V5

Not known to be exploited : upgrade to 0.4019 when convenient.

Data as of 25 Oct 2026, 17:13 UTC

Severity

Medium

Rated Medium by the CNA (CPANSec) · CVSS not yet scored by NVD

Patch: Available – fixed in 0.4019

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Starman (Perl module) to 0.4019.

Affected software

Product	Affected	Fixed in
CPANStarman`pkg:cpan/Starman`Other threats	Affected <0.4019	Fixed in 0.4019

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade to Starman version 0.4019 or later where this issue is presumably fixed. Until then, consider implementing external protections such as request size limits or filtering malformed chunked requests at a proxy or firewall level.

Description

CVE-2026-115822 is a vulnerability in Starman for Perl versions before 0.4019 that allows remote attackers to cause CPU exhaustion via inefficient regular expression processing. The issue arises from quadratic regex backtracking when parsing chunked request bodies, specifically due to a regex that fails to match certain malformed chunk-size lines, leading to excessive CPU usage. This can be triggered by sending crafted requests to any route handled by the server.

Impact

A remote attacker can cause denial of service by exhausting the CPU of a Starman worker process through crafted HTTP requests with malformed chunked transfer encoding. This can degrade service availability or cause service interruptions.

Summary

Starman versions prior to 0.4019 contain a vulnerability involving inefficient regular expression complexity (CWE-1333). When decoding chunked request bodies, Starman uses the regex `s/^(([0-9a-fA-F]+).*\015\012)//` to match chunk-size lines. However, lines consisting of hex digits followed by a bare LF and then CRLF do not match because the dot character does not match LF. Each failed match attempt causes quadratic backtracking proportional to the length of the hex digits, resulting in CPU exhaustion. There is no limit on the length of these lines, enabling a remote attacker to exhaust worker CPU resources by sending specially crafted requests.

CWE-1333Inefficient Regular Expression Complexity (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
Regular Expression Exponential Blowup (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 17:11 UTC

WeaknessesCWE-1333

Technical details

References

Community reviews

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