CVE-2025-37778: debian debian_linux Use After Free

Vulnerability summary

CVE-2025-37778 is a critical (CVSS 9.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 1.14% chance of exploitation in the next 30 days, higher than 66.1% of scored vulnerabilities.

Timeline

1. 01-05-2025
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix dangling pointer in krb_authenticate krb_authenticate frees sess->user and does not set the pointer to NULL. It calls ksmbd_krb5_authenticate to reinitialise sess->user but that function may return without doing so. If that happens then smb2_sess_setup, which calls krb_authenticate, will be accessing free'd memory when it later uses sess->user.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.