---
id: CVE-2026-92823
title: >-
  Libmodulemd: libmodulemd: missing decompressed-size limit when parsing
  compressed yaml
summary: >-
  A flaw was found in libmodulemd. In builds with rpmio support enabled,
  compressed modulemd YAML is decompressed through a custom read handler that
  does not enforce a cumulative decompressed-size limit before parsing. An
  attacker who can …
severity: medium
cvss: 6.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-409
vendor: Red Hat
product: libmodulemd
affected:
  - libmodulemd (all versions)
  - libmodulemd (all versions)
  - libmodulemd (all versions)
  - libmodulemd (all versions)
  - openshift/ose-rhel-coreos-8 (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T03:23:10.549Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-92823'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-92823'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2478703'
    label: RHBZ#2478703
tags:
  - cve.org
ingestedAt: '2026-10-21T06:42:48.209Z'
---

## Overview

A flaw was found in libmodulemd. In builds with rpmio support enabled, compressed modulemd YAML is decompressed through a custom read handler that does not enforce a cumulative decompressed-size limit before parsing. An attacker who can supply a highly compressible compressed YAML file can cause excessive CPU and memory consumption, resulting in a denial of service.

## Affected

- `libmodulemd (all versions)`
- `libmodulemd (all versions)`
- `libmodulemd (all versions)`
- `libmodulemd (all versions)`
- `openshift/ose-rhel-coreos-8 (all versions)`
- `openshift/ose-rhel-coreos-9 (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

Until a fix is available, avoid parsing attacker-controlled compressed module metadata in rpmio-enabled builds. Where compressed input is required, decompress outside the process under strict size quotas, or reject files whose decompressed size exceeds a conservative limit before passing data to libmodulemd. Building without rpmio support removes the affected path.