CVE-2026-99083

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds…

Risk score: 65/100
CVSS: 8.8 v3.1
Exploit chance (30 days): 0.2%
Published: 23 Oct 2026

Open in the live forecast Today's forecast

What to know

What it is: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds write in krb5_authenticate() In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-fir…
Affected: See advisory
Fix: Apply the vendor's security update; see the linked advisory.
Exploitation: No known exploitation

Why it is Amber

CVSS 8.8 high
On your watchlist: linux kernel

References

Original description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds write in krb5_authenticate() In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-first element of a compounded SMB2 request, the calculation omits work->next_smb2_rsp_hdr_off. This causes out_len to overstate remaining buffer headroom by the cumulative size of prior responses in the compound chain. Consequently, the length check in ksmbd_krb5_authenticate() (*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy() to write the AP-REP blob past the end of response_buf into adjacent kernel heap memory. Fix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len, ensuring it accurately reflects physical remaining buffer space.

Last activity 23 Oct 2026. Patch Forecast updates every hour.