UBUNTU-CVE-2026-115865: Medium severity ubuntu/starlet vulnerability
Starlet versions before 0.33 for Perl allow a request declaring a large Content-Length to kill a worker by exhausting memory. The request body is read in a loop that asks sysread for all of the remaining declared length at once. Perl grows the read buffer to that size before any data arrives, so a length larger than available memory makes the worker exit with an uncatchable out of memory error before the application is called. A remote attacker can force a worker restart with each request of a few bytes.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Starletto a version that resolves this vulnerability.Fixed in 0.33
Event History
Frequently Asked Questions
Which deployments are exposed?
Starlet versions before 0.33 for Perl are affected. The issue can be triggered remotely by a client sending an HTTP request with an excessively large declared Content-Length.
What does an attacker need to send to trigger the failure?
The attacker only needs to declare a Content-Length larger than the worker's available memory; the actual request body can be only a few bytes. The resulting out-of-memory error occurs before the application is called and causes the worker to exit.