Vulnerability · Published Oct 25, 2026 · Assigned by CPANSec
CVE-2026-115822Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies
High 7.5
In plain English
A high-severity regular-expression denial of service in Starman. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | starman | no fix listed | DEBIAN-CVE-2026-115822 |
| Debian:13 | starman | no fix listed | DEBIAN-CVE-2026-115822 |
| Debian:14 | starman | 0.4019-1 | DEBIAN-CVE-2026-115822 |
| Ubuntu:22.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115822 |
| Ubuntu:24.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115822 |
| Ubuntu:26.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115822 |
| Ubuntu:26.10 | starman | no fix listed | UBUNTU-CVE-2026-115822 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Starman | 0 – before 0.4019 |
Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H