CVE-2026-25506
Published: 10 February 2026
Summary
CVE-2026-25506 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Opensuse Munge. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 6.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Flaw remediation directly addresses the CVE by requiring timely patching of the buffer overflow in munged to version 0.5.18, preventing key leakage and credential forgery.
Information input validation enforces checks on message fields like address length, directly preventing the oversized input that triggers the buffer overflow.
Memory protection mechanisms such as stack canaries, ASLR, and non-executable stacks mitigate buffer overflow exploitation by limiting memory corruption and unauthorized access to cryptographic key material.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Buffer overflow in local MUNGE daemon directly enables exploitation for privilege escalation (T1068) via memory disclosure of MAC signing key (T1552.004 Private Keys); stolen key material then facilitates forging valid MUNGE credentials as alternate authentication material (T1550.001 Application Access Token) to impersonate any user including root.
NVD 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…
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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.
Deeper analysisAI
CVE-2026-25506 is a buffer overflow vulnerability (CWE-787) in the munged daemon of MUNGE, an authentication service for creating and validating user credentials, affecting versions 0.5 through 0.5.17. The flaw occurs when munged processes a crafted message with an oversized address length field, leading to corruption of the daemon's internal state and leakage of cryptographic key material, specifically the MAC subkey used for credential verification, from process memory. The vulnerability has a CVSS v3.1 base score of 7.7 (AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L).
A local attacker with low privileges can exploit this vulnerability by sending the malicious message to munged, enabling them to extract the sensitive key material. Armed with the leaked MAC subkey, the attacker can forge arbitrary MUNGE credentials, impersonating any user—including root—on services that rely on MUNGE for authentication, potentially leading to full system compromise in affected environments.
The issue is addressed in MUNGE version 0.5.18, as detailed in the GitHub release announcement, the fixing commit (bf40cc27c4ce8451d4b062c9de0b67ec40894812), and the security advisory (GHSA-r9cr-jf4v-75gh). Additional discussions, including patch details, appear on the oss-security mailing lists in February 2026.
Details
- CWE(s)