CVE-2026-99083
ksmbd: fix heap out-of-bounds write in krb5_authenticate()
No known exploitation. No EPSS score yet. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- LinuxAffected: ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 59c6dcc5dd9dafe764ca0d40525933b2be69b059Upgrade to: 59c6dcc5dd9dafe764ca0d40525933b2be69b059Affected: ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 80af1bde97d5a85ad6f2c40ca894ccc8fa75a27aUpgrade to: 80af1bde97d5a85ad6f2c40ca894ccc8fa75a27aAffected: ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 517404e157395d0f8da125ca956c566895dfcd06Upgrade to: 517404e157395d0f8da125ca956c566895dfcd06Affected: ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 4722d06b2907585074252061b1024a696c1cfc23Upgrade to: 4722d06b2907585074252061b1024a696c1cfc23 + 5 more branchesStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
No EPSS score yet. New CVEs are usually scored within a few days.
Lifecycle
2 events over 0 days, from the signal feeds we watch.
- Publishedrecord updated
Affected products
Sources
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