Vulnerability · Published Oct 25, 2026 · Assigned by CPANSec
CVE-2026-115823Starman versions before 0.4019 for Perl send response bodies for HEAD requests, desynchronizing responses on keep-alive connections
Critical 9.1
In plain English
A critical-severity security flaw in Starman. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Starman versions before 0.4019 for Perl send response bodies for HEAD requests, desynchronizing responses on keep-alive connections. For a HEAD request Starman omits chunked framing but still writes the body returned by the application, on both the array and streaming response paths. Responses with a 1xx, 204 or 304 status also carry the body. On a keep-alive or pipelined connection the client reads those bytes as the start of the next response. A front-end proxy that reuses upstream connections may then pair responses with the wrong requests.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | starman | no fix listed | DEBIAN-CVE-2026-115823 |
| Debian:13 | starman | no fix listed | DEBIAN-CVE-2026-115823 |
| Debian:14 | starman | 0.4019-1 | DEBIAN-CVE-2026-115823 |
| Ubuntu:22.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115823 |
| Ubuntu:24.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115823 |
| Ubuntu:26.04:LTS | starman | no fix listed | UBUNTU-CVE-2026-115823 |
| Ubuntu:26.10 | starman | no fix listed | UBUNTU-CVE-2026-115823 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Starman | 0 – before 0.4019 |
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N