This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
Description
This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
Analysis
No data.
No data.
| Vendor | Product | Confidence | Versions | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux Kernel | 99% |
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| Linux | Linux Kernel | 99% |
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Remediation
No vendor fix or workaround currently provided.
OpenCVE Recommended Actions
- Update the Linux kernel to a version that includes the ksmbd patch that introduces the correct per‑channel key sizing.
- If a kernel update is not possible, disable SMB multichannel support or enforce a limit on the session key length to prevent large key values from being processed.
- Restrict SMB access to trusted clients and configure the server to reject NTLM sessions that use the key exchange flag or to reject Kerberos tickets with session keys larger than 16 bytes.
Generated by OpenCVE AI on August 15, 2026 at 07:59 UTC.
Tracking
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Advisories
No advisories yet.
References
History
Tue, 18 Aug 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | kernel: ksmbd: fix stack buffer overflow in multichannel session-key copy | |
| References |
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| Metrics |
threat_severity
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cvssV3_1
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Mon, 17 Aug 2026 06:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Mon, 17 Aug 2026 05:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix stack buffer overflow in multichannel session-key copy Commit 4b706360ffb7 ("ksmbd: fix multichannel binding and enforce channel limit") moved the binding-path session key out of the session-wide sess->sess_key (CIFS_KEY_SIZE = 40) into a new per-channel buffer, and sized both that buffer and the on-stack copy used during binding with SMB2_NTLMV2_SESSKEY_SIZE (16): struct channel { char sess_key[SMB2_NTLMV2_SESSKEY_SIZE]; /* 16 */ ... }; ntlm_authenticate() / krb5_authenticate(): char channel_key[SMB2_NTLMV2_SESSKEY_SIZE] = {}; /* 16 */ char *auth_key = conn->binding ? channel_key : sess->sess_key; The two writers that fill this destination still bound the copy length against CIFS_KEY_SIZE (40), not against the 16-byte buffer: ksmbd_decode_ntlmssp_auth_blob() (NTLM key exchange): if (sess_key_len > CIFS_KEY_SIZE) /* 40 */ return -EINVAL; arc4_crypt(ctx_arc4, sess_key, (char *)authblob + sess_key_off, sess_key_len); ksmbd_krb5_authenticate(): if (resp->session_key_len > sizeof(sess->sess_key)) /* 40 */ ... memcpy(sess_key, resp->payload, resp->session_key_len); On a binding SESSION_SETUP, auth_key points at the 16-byte channel_key, so a client that supplies an NTLM EncryptedRandomSessionKey of up to 40 bytes (with NTLMSSP_NEGOTIATE_KEY_EXCH), or a Kerberos ticket whose session key is longer than 16 bytes (a normal AES256 key is 32), writes past the 16-byte stack buffer -- up to a 24-byte kernel stack overflow. KASAN reports it as a stack-out-of-bounds write in arc4_crypt() called from ksmbd_decode_ntlmssp_auth_blob(). The destinations must be able to hold the full session key the length checks already permit. Size the per-channel key buffer and the two on-stack channel_key buffers with CIFS_KEY_SIZE, matching sess->sess_key. | This CVE ID has been rejected or withdrawn by its CVE Numbering Authority. |
| Title | ksmbd: fix stack buffer overflow in multichannel session-key copy | |
| CPEs |
Sat, 15 Aug 2026 08:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-120 |
Sat, 15 Aug 2026 06:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix stack buffer overflow in multichannel session-key copy Commit 4b706360ffb7 ("ksmbd: fix multichannel binding and enforce channel limit") moved the binding-path session key out of the session-wide sess->sess_key (CIFS_KEY_SIZE = 40) into a new per-channel buffer, and sized both that buffer and the on-stack copy used during binding with SMB2_NTLMV2_SESSKEY_SIZE (16): struct channel { char sess_key[SMB2_NTLMV2_SESSKEY_SIZE]; /* 16 */ ... }; ntlm_authenticate() / krb5_authenticate(): char channel_key[SMB2_NTLMV2_SESSKEY_SIZE] = {}; /* 16 */ char *auth_key = conn->binding ? channel_key : sess->sess_key; The two writers that fill this destination still bound the copy length against CIFS_KEY_SIZE (40), not against the 16-byte buffer: ksmbd_decode_ntlmssp_auth_blob() (NTLM key exchange): if (sess_key_len > CIFS_KEY_SIZE) /* 40 */ return -EINVAL; arc4_crypt(ctx_arc4, sess_key, (char *)authblob + sess_key_off, sess_key_len); ksmbd_krb5_authenticate(): if (resp->session_key_len > sizeof(sess->sess_key)) /* 40 */ ... memcpy(sess_key, resp->payload, resp->session_key_len); On a binding SESSION_SETUP, auth_key points at the 16-byte channel_key, so a client that supplies an NTLM EncryptedRandomSessionKey of up to 40 bytes (with NTLMSSP_NEGOTIATE_KEY_EXCH), or a Kerberos ticket whose session key is longer than 16 bytes (a normal AES256 key is 32), writes past the 16-byte stack buffer -- up to a 24-byte kernel stack overflow. KASAN reports it as a stack-out-of-bounds write in arc4_crypt() called from ksmbd_decode_ntlmssp_auth_blob(). The destinations must be able to hold the full session key the length checks already permit. Size the per-channel key buffer and the two on-stack channel_key buffers with CIFS_KEY_SIZE, matching sess->sess_key. | |
| Title | ksmbd: fix stack buffer overflow in multichannel session-key copy | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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MITRE
Status: REJECTED
Assigner: Linux
Published:
Updated: 2026-08-17T05:31:43.380Z
Reserved: 2026-08-09T03:40:39.902Z
Link: CVE-2026-72044
Vulnrichment
No data.
NVD
Status : Rejected
Published: 2026-08-15T06:21:13.600
Modified: 2026-08-17T06:18:02.397
Link: CVE-2026-72044
Redhat
OpenCVE Enrichment
Updated: 2026-08-15T09:45:03Z
Weaknesses
-
CWE-120
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')