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CVE-2026-60109 zeek CVE debrief

CVE-2026-60109 is a null pointer dereference vulnerability in Zeek's Kerberos protocol analyzer. Unauthenticated remote attackers can 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. The vulnerability arises from a parser and analyzer state mismatch where proc_padata() dereferences an uninitialized pa_data_element field selected by the wrong parsing arm. This issue can lead to a denial-of-service attack, potentially disrupting network monitoring and security operations.

Vendor
zeek
Product
Unknown
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-09
Original CVE updated
2026-07-10
Advisory published
2026-07-09
Advisory updated
2026-07-10

Who should care

Users of Zeek versions prior to 8.0.9 should apply the patch to prevent unauthenticated remote denial-of-service attacks. Additionally, security teams and vulnerability management teams should review the vulnerability details to assess the impact on their systems and prioritize patching accordingly. Zeek administrators and operators should also verify the configuration and ensure that the sensor is properly secured.

Technical summary

The vulnerability is caused by a null pointer dereference in the Kerberos protocol analyzer of Zeek. An unauthenticated remote attacker can exploit this by sending a specially crafted KRB_ERROR message, which can cause the sensor to crash. The message must have error-code 25 (KDC_ERR_PREAUTH_REQUIRED) and contain a PA-DATA element with specific padata-type values (2, 3, 11, or 19). This issue results from a mismatch in the parser and analyzer states, leading to the dereference of an uninitialized field. The vulnerability can be mitigated by applying the official patch and implementing additional security measures.

Defensive priority

High

Recommended defensive actions

  • Apply the official patch (Zeek version 8.0.9 or later) to fix the null pointer dereference vulnerability.
  • Implement network monitoring to detect and block suspicious Kerberos traffic.
  • Restrict access to the Zeek sensor to trusted sources only.
  • Regularly update and patch Zeek installations to ensure the latest security fixes are applied.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-07-09T15:16:41.757Z and has been modified on 2026-07-10T20:08:41.227Z. The NVD entry is currently Analyzed. The vulnerability details are based on the information available from the CVE record and NVD entry. However, the specific technical details and impact of the vulnerability are limited, and further verification is recommended. Users should review the official advisory and CVE record for the most up-to-date information.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-09T15:16:41.757Z and has not been modified since then. The NVD entry is currently Analyzed.