NULL pointer dereference in Zeek
CVE-2026-60109
Zeek before 8.0.9 contains a null pointer dereference vulnerability in its Kerberos protocol analyzer that allows unauthenticated remote attackers to crash the sensor by sending a crafted KRB_ERROR message with error-code 25 (KDC_ERR_PREAUTH_REQUIRED) containing a PA-DATA element with padata-type 2, 3, 11, or 19. Attackers can exploit a parser and analyzer state mismatch where proc_padata() dereferences an uninitialized pa_data_element field selected by the wrong parsing arm, triggering a crash via a single UDP or TCP packet to port 88 without any credentials or prior authentication.
EPSS: 0.005 (41.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Zeek — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (release-notes, Release Notes)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-60109?
- CVE-2026-60109 is a high-severity vulnerability in Zeek, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-07-09.
- How severe is CVE-2026-60109?
- High severity. CVSS v3 base score is 7.5 out of 10.