What’s Vulnerable › Vulnerabilities

CVE-2026-60109: Zeek < 8.0.9 Null Pointer Dereference DoS via Kerberos KRB_ERROR Parsing

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-09 · updated 2026-10-23
• Weakness: CWE-476

Description

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.

Affected products

• zeek: before 8.0.9 — fixed in 8.0.9

How to fix

Upgrade to a fixed version: zeek 8.0.9. Check the vendor advisory for mitigations.

References

• https://github.com/zeek/zeek/commit/c82e3c734893d932e94310aec0dbeb1ffcea169d
• https://github.com/zeek/zeek/releases/tag/v8.0.9
• https://www.vulncheck.com/advisories/zeek-null-pointer-dereference-dos-via-kerberos-krb-error-parsing

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