Starman for Perl lets remote attackers exhaust CPU via chunked bodies
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-1333.
Summary
Starman versions before 0.4019 for Perl decode chunked request bodies with a regular expression that backtracks quadratically (CWE-1333). A chunk-size line of hex digits followed by a bare LF never matches, and the cost grows with the length of the hex run, which nothing limits. A remote unauthenticated attacker can exhaust worker CPU by sending such requests to any route.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Starman | before 0.4019 | 0.4019 | Patch available | CNA |
- Starman Vendor— Affected before 0.4019 Fixed in 0.4019 Patch available CNA
Remediation
Update Starman to version 0.4019, which is the fixed version.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Starman Fixed in 0.4019
Vendor assessments
Timeline
- 2026-10-25 Threatist record created from CVE-2026-115822
- 2026-10-27 Alias added: GHSA-2826-qw6w-9h42
- 2026-11-02 CVSS score added · CISA ADP
- 2026-11-02 CISA SSVC decision points changed
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
Sources
- CVE-2026-115822 · CVE Program
- CVE-2026-115822 · NVD
- FIRST EPSS
- GHSA-2826-qw6w-9h42 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-115822 · Red Hat security data · CC BY 4.0
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