ksmbd: fix heap out-of-bounds write in krb5_authenticate()
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.
CVE-2026-99083
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-99083
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "59c6dcc5dd9dafe764ca0d40525933b2be69b059",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "517404e157395d0f8da125ca956c566895dfcd06",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "4722d06b2907585074252061b1024a696c1cfc23",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "23a0be6a84a38ac169eeab49017934e8e27c65f0",
"versionType": "git"
},
{
"status": "affected",
"version": "0",
"lessThan": "6.6.160",
"versionType": "semver"
},
{
"status": "affected",
"version": "0",
"lessThan": "6.12.114",
"versionType": "semver"
},
{
"status": "affected",
"version": "0",
"lessThan": "6.18.58",
"versionType": "semver"
},
{
"status": "affected",
"version": "0",
"lessThan": "7.2.12",
"versionType": "semver"
}
],
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.58",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.12",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-99083
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #55752 · Revision 1
- Added to Heist Feed
- Publisher date