VulnerabilityModified
CVE-2026-40355
An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.
HIGH 7.5EPSS 0.61%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.61% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- mit/kerberos 5
- Source
- cve@mitre.org
References
- https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.htmlExploit, Patch, Third Party Advisory
- https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929fPatch
- https://web.mit.edu/kerberos/advisories/Vendor Advisory
- https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.htmlExploit, Patch, Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.