smb: client: reject short SESSION_SETUP responses
Severity and exploitation
KEV coverage does not rule out exploitation.
Severity
unknownCVSS measures technical severity, not the likelihood of an attack.
Known exploitation
Not listed in the checked CISA KEV catalog
Absence from CISA KEV does not rule out attacks.
Public exploit
Not established by this record
Missing evidence does not mean no public exploit exists.
Remediation
Fix status not established
No structured fix or guidance is available here. Check the latest publisher advisory.
What this means
In the Linux kernel, the following vulnerability has been resolved:
Source excerpt · LinuxAttack conditions
No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.
Review supporting sources →Affected versions
Check the exact model, release, and any platform requirements against your installation.
Linux · Linux
Linux
2 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
5478f9ba9a34d660eb3227dcd16314689c51f946 → before df63e01933886153e40706483b9635b2456ad91f
git versions
5478f9ba9a34d660eb3227dcd16314689c51f946 → before 4d8930afa3446041358a7db33e7b23a0bb9459b5
git versions
Other versions: unaffected
Linux · Linux
Linux
4 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
3.6
unaffected
0 → before 3.6
semver versions
7.3.2 → through 7.3.*
semver versions
7.4-rc1 → through *
original_commit_for_fix versions
Other versions: affected
What to do
Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.
No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.
cve.new guidance unless attributed to a publisher. This page does not inspect your installation.
Public exploit evidence
No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.
Original source description
Read the full publisher description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject short SESSION_SETUP responses
smb2_check_message() accepts frames shorter than struct smb2_pdu when the SMB2 status is non-zero, before the minimum-PDU check added by b4694f269e66d. A 64-byte STATUS_MORE_PROCESSING_REQUIRED SESSION_SETUP response is therefore accepted even though it cannot contain the SecurityBufferOffset and SecurityBufferLength fields.
The parser then reads those fields from stale bytes left in the reused receive buffer by an earlier frame. With a long stale SecurityBufferLength, decode_ntlmssp_challenge() copies up to about 64 KB from beyond the receive object and sends the data back to the server in the NTLMv2 AUTHENTICATE target info.
Reject short MPR SESSION_SETUP responses before the short-error path, and validate SecurityBufferOffset + SecurityBufferLength against the received response length before decoding the challenge.
The ordering bypass is not new: the short-error early return predates b4694f269e66d, and the unvalidated SecurityBufferLength read predates the 2016 raw NTLMSSP split in 166cea4dc3a4, so all supported stable trees are affected. Reproduced on 6.6.87.2; the path is unchanged on mainline.
References
2 sourcesInside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-99275View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Environment requirements
These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.
Linux · platform conditions
Any condition may hold
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 3.6
Before: 7.3.2
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 3.6
Before: 7.4-rc1
Applicability preview
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]Contributing organizations · 1
Assigning organization
Timeline
All times UTCAdvisory published
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Last imported by cve.new
Latest catalog import, not the date we first saw this advisory.
What changed
Follow changesLarge field values are marked as truncated previews. Original source snapshots remain retained.