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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.009 (59.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Zeek — versions 0
Weakness classification (CWE)
References
- github.com/zeek/zeek/releases/tag/v8.0.9 (release-notes, Release Notes)
- github.com/zeek/zeek/commit/c82e3c734893d932e94310aec0dbeb1ffcea169d (Patch, patch)
- www.vulncheck.com/advisories/zeek-null-pointer-dereference-dos-via-kerberos-krb… (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.