CVE-2026-25506

Modified Modified - Updated After Analysis

Buffer Overflow in MUNGE Daemon Allows Credential Forgery

Publication date: 2026-02-10

Last updated on: 2026-06-30

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-02-10

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-02-10

EPSS Evaluated

2026-07-05

NVD

CVE-2026-25506

EUVD

EUVD-2026-6734

Affected Vendors & Products

Vendor	Product	Version / Range
debian	debian_linux	11.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-120	The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability exists in MUNGE, an authentication service used to create and validate user credentials. Specifically, versions 0.5 to 0.5.17 of the munged daemon have a buffer overflow flaw. A local attacker can send a specially crafted message with an oversized address length field, causing a buffer overflow that corrupts munged's internal state.

This corruption allows the attacker to extract cryptographic key material (the MAC subkey) from the process memory. With this leaked key, the attacker can forge arbitrary MUNGE credentials and impersonate any user, including root, to services relying on MUNGE for authentication.

The issue is fixed in version 0.5.18.

Impact Analysis

This vulnerability can have serious security impacts. An attacker with local access can exploit it to leak cryptographic keys used for authentication.

By obtaining these keys, the attacker can forge credentials and impersonate any user, including privileged users like root.

This can lead to unauthorized access to systems and services that rely on MUNGE for authentication, potentially compromising system integrity, confidentiality, and availability.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade MUNGE to version 0.5.18 or later, where the buffer overflow issue in munged has been fixed.

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