---
id: "CVE-2026-92823"
kind: "vulnerability"
aliases: ["CVE-2026-92823"]
title: "libmodulemd: unbounded decompression of compressed YAML causes denial of service"
severity: "medium"
cvss: 6.2
epss: 0.00117
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["build-tooling", "libmodulemd", "package", "rpm-based-distros"]
not_affected_if: ["default-config", "trusted-input-only"]
published_at: "2026-10-21T04:18:12+00:00"
first_seen_at: "2026-10-23T21:57:28+00:00"
updated_at: "2026-10-25T04:02:01+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92823", "first_seen_at": "2026-10-23T21:57:28+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-92823", "first_seen_at": "2026-10-24T13:15:54+00:00"}]
---

# libmodulemd: unbounded decompression of compressed YAML causes denial of service

libmodulemd, a library for parsing Fedora/RHEL modulemd metadata, does not cap the total decompressed size of compressed YAML in builds with rpmio support. A crafted, highly compressible file can exhaust CPU and memory on the parsing host.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:28+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-92823
- 2026-10-24T13:15:54+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-92823

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_