CVE-2026-40356

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.60% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 46.5% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-07-08.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-28 00:00Z4 MO AGO

Last updated

2026-04-28 13:10Z4 MO AGO

Reserved

2026-04-11

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

• CWE-191Integer Underflow (Wrap or Wraparound)Base

Data version

5.2

Document digest

d53cba1bdc9a7bf99f7551ed4850830957b66fe90f628ff1d44d971686cbc45e

• web.mit.eduhttps://web.mit.edu/kerberos/advisories/
• cems.funhttps://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html
• github.comhttps://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f