PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-25506 dun CVE debrief

A buffer overflow vulnerability was discovered in MUNGE, a user credential authentication service, from version 0.5 to 0.5.17. This vulnerability allows a local attacker to exploit munged, the MUNGE authentication daemon, potentially leaking cryptographic key material from process memory. With the leaked key material, an attacker could forge arbitrary MUNGE credentials to impersonate any user, including root, to services that rely on MUNGE for authentication. The vulnerability is caused by sending a crafted message with an oversized address length field, which corrupts munged's internal state and enables extraction of the MAC subkey used for credential verification. The issue has been fixed in version 0.5.18.

Vendor
dun
Product
munge
CVSS
HIGH 7.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-02-10
Original CVE updated
2026-07-15
Advisory published
2026-02-10
Advisory updated
2026-07-15

Who should care

System administrators and security teams responsible for MUNGE installations, particularly those using versions between 0.5 and 0.5.17, should be aware of this vulnerability. This vulnerability could allow a local attacker to gain elevated privileges and access sensitive information. Debian Linux users, specifically those using Debian 11.0, are affected by this vulnerability.

Technical summary

The CVE-2026-25506 vulnerability is a buffer overflow issue in the MUNGE authentication service. The vulnerability exists in versions 0.5 through 0.5.17 of MUNGE. An attacker can exploit this vulnerability by sending a specially crafted message to the munged daemon, which can lead to a buffer overflow and corruption of internal state. This corruption enables the extraction of the MAC subkey used for credential verification, allowing an attacker to forge arbitrary MUNGE credentials. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 7.7, indicating a high severity level. The CVSS vector is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L.

Defensive priority

High priority should be given to updating MUNGE to version 0.5.18 or later. System administrators should ensure that MUNGE installations are updated as soon as possible to prevent potential exploitation.

Recommended defensive actions

  • Update MUNGE to version 0.5.18 or later.
  • Review and update affected systems, particularly those using Debian 11.0.
  • Monitor system logs for suspicious activity related to MUNGE.
  • Implement additional security measures, such as restricting access to MUNGE services.
  • Verify the integrity of MUNGE installations and configurations.

Evidence notes

The CVE-2026-25506 vulnerability was publicly disclosed on February 10, 2026, and has been modified on June 30, 2026. The vulnerability affects MUNGE versions from 0.5 to 0.5.17. Debian Linux 11.0 is known to be affected. The vulnerability allows a local attacker to potentially leak cryptographic key material and impersonate users. The issue has been fixed in MUNGE version 0.5.18.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-25506 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-25506

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-25506 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-25506

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.