CVE-2026-25506: MUNGE has a buffer overflow in message unpacking allows key leakage and credential forgery
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
munged (MUNGE authentication daemon)to a version that resolves this vulnerability.Fixed in 0.5.18 - Compensating control
Because the vulnerability can leak MUNGE cryptographic key material and enable credential forgery, restrict network access to the MUNGE authentication service (munged) so only trusted clients/hosts can send MUNGE messages to it (e.g., via firewall/ACL).
Event History
Frequently Asked Questions
What is the severity of CVE-2026-25506?
CVE-2026-25506 is classified as a high severity vulnerability due to its potential for key leakage and credential forgery.
How do I fix CVE-2026-25506?
To fix CVE-2026-25506, upgrade MUNGE to version 0.5.18 or later to mitigate the buffer overflow issue.
Who is affected by CVE-2026-25506?
CVE-2026-25506 affects MUNGE versions from 0.5.0 to 0.5.17, potentially exposing local systems to exploitation.
What type of attack is possible with CVE-2026-25506?
CVE-2026-25506 allows local attackers to exploit a buffer overflow, leading to key leakage and possible credential forgery.
What is MUNGE and how does CVE-2026-25506 impact it?
MUNGE is an authentication service for managing user credentials, and CVE-2026-25506 compromises its security through a buffer overflow vulnerability.