# CVE-2026-115864: Monoceros versions before 0.30 for Perl allow a request declaring a large Content-Length to kill a worker by exhausting memory

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

Monoceros versions before 0.30 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.

## Remediation

- fix: Upgrade to Monoceros 0.30 or later. (source: CNA: CPANSec)
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: CPANSec) — https://github.com/kazeburo/Monoceros/commit/897a4a9624329fc0a4b2352d387bdac6d37848e2.patch

## Affected products and versions

-  /  (Monoceros): ≥ 0; < 0.30 (affected, custom). Source: CNA: CPANSec

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-789

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/kazeburo/Monoceros/commit/897a4a9624329fc0a4b2352d387bdac6d37848e2.patch (CNA: CPANSec; patch)

- https://metacpan.org/release/KAZEBURO/Monoceros-0.30/changes (CNA: CPANSec; release-notes)

## Provenance

- CNA: CPANSec: https://www.cve.org/CVERecord?id=CVE-2026-115864; retrieved 2026-11-09; source updated 2026-11-09

Revision: 90e8f97b2a4fefe116690bb617e2a03345f7b433710a4bdcaf808cf8b518031a

Canonical: https://y2.dev/cve/CVE-2026-115864

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