Security readout for executives and security teams
Plain-English summary
This is a Linux kernel CIFS/SMB2 client bug where a failed negotiation path can leak a small mempool buffer instead of freeing it. The available sources do not provide CVSS, CWE, distribution impact, or active exploitation evidence.
Executive priority
Treat as routine kernel maintenance unless your environment depends heavily on Linux CIFS mounts. There is no source-backed active exploitation claim, but affected kernels should still be updated through normal patch cycles.
Technical view
In SMB2_negotiate(), some dialect-mismatch failure paths return -EIO after sending the request, bypassing the neg_exit cleanup path that frees the response buffer from the mempool. Stable kernel commits correct the error path to release the buffer.
Likely exposure
Likely limited to Linux systems running affected kernel builds with CIFS/SMB2 client functionality in use. The source bundle lists Linux kernel versions and commits, but not specific distributions or appliances.
Exploitation context
The sources describe a cleanup bug during SMB2 negotiation failure, not a public exploit. KEV is false, and no cited source states active exploitation or weaponized abuse.
Researcher notes
The useful validation point is code lineage: confirm whether SMB2_negotiate() includes the cleanup-path fix for dialect mismatch failures. Distribution package versions require vendor mapping because the CVE data does not provide distro-specific fixed releases.
Mitigation direction
- Map deployed kernels to vendor advisories for CVE-2022-49938.
- Update to kernel builds containing the referenced stable fixes.
- Prioritize systems that actively mount SMB/CIFS shares.
- Monitor vendor security channels for distribution-specific backports.
Validation and detection
- Inventory Linux kernel versions across affected fleets.
- Confirm whether CIFS/SMB2 client functionality is enabled or used.
- Check vendor changelogs for the stable fix commits.
- Review logs for repeated SMB negotiation failures where relevant.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2022-49938 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/9e3c9efa7caf16e5acc05eab5e4d0a714e1610b0CVE reference, Linux
- https://git.kernel.org/stable/c/38a6b469bf22f153282fbe7d702a24e9eb43f50eCVE reference, Linux
- https://git.kernel.org/stable/c/27893dfc1285f80f80f46b3b8c95f5d15d2e66d0CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.