# CVE-2026-92823: Libmodulemd: libmodulemd: missing decompressed-size limit when parsing compressed yaml

Status: published. Published: 2026-10-21. Updated: 2026-11-06.

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.

## Remediation

- workaround: 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. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (libmodulemd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (libmodulemd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (libmodulemd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (libmodulemd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.2 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.16% as of 2026-11-05; percentile 5.23%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-409

## Exploit evidence

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

## References

- https://access.redhat.com/security/cve/CVE-2026-92823 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2478703 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/advisories/GHSA-x9m8-9g38-v659 (CNA: redhat)

- https://github.com/fedora-modularity/libmodulemd/pull/644 (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-92823; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-92823; retrieved 2026-11-06; source updated Not reported

Revision: eb914f841bb9f57dd337dd09ff908d74a0afdedce241761ba2a1207074fe07be

Canonical: https://y2.dev/cve/CVE-2026-92823

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