CVE-2026-116127
What it is
Starlet versions before 0.33 for Perl send a body in responses to HEAD requests, corrupting the next response on a persistent or pipelined connection. The request method is not passed to the response writer, so whatever body the application returns for a HEAD request is sent. With Plack::Middleware::Head the body is empty, but an HTTP/1.1 response without a Content-Length header still gets the chunked encoding terminator. Responses with status 204 or 304 are also sent with their body. Pipelined GET and HEAD requests keep the connection open even when keep-alive is disabled, which is the default. A client or proxy reading the connection takes the extra bytes as the start of the next response, which may desynchronize a proxy that shares the connection across clients.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data tampering, service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-444
- Record status
- Deferred
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-116127.md and follow it. Check whether this project is affected by CVE-2026-116127. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
