Answer in brief
CVE-2026-68431 records a Unknown severity vulnerability in ksmbd: validate minimum PDU size for transform requests. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <b62c510f59803f82f9b4c76ead2a56833b2984c7 || >=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <cfc0b8e5080aec87700774e8568765eaa4b7b92b || df3a4518aee64f21bcafa891105b468413f27431 || 543c12c2644e772caa6880662c2a852cfdc5a10c || e9cb7be2fcbaee9e808b729e92948d38d52e5add || >=5.15.145 <5.16 || >=6.1.34 <6.2 || >=6.3.8 <6.4 | b62c510f59803f82f9b4c76ead2a56833b2984c7, cfc0b8e5080aec87700774e8568765eaa4b7b92b, 5.16, 6.2, 6.4 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 2026
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate minimum PDU size for transform requests The receive path applies the minimum SMB2 PDU size check only when ProtocolId is SMB2_PROTO_NUMBER. A packet carrying SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated dialect does not provide transform handling. On an SMB 2.1 connection, a short transform packet therefore reaches init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header and reads beyond the request allocation. The copied fields can then be returned to the unauthenticated client. Compression transforms are converted to ordinary SMB2 messages before protocol validation. After that conversion, validate ordinary SMB2 requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption transform requests to contain both a transform header and an SMB2 header. This rejects truncated requests before work allocation.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-68431 records a Unknown severity vulnerability in ksmbd: validate minimum PDU size for transform requests. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <b62c510f59803f82f9b4c76ead2a56833b2984c7 || >=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <cfc0b8e5080aec87700774e8568765eaa4b7b92b || df3a4518aee64f21bcafa891105b468413f27431 || 543c12c2644e772caa6880662c2a852cfdc5a10c || e9cb7be2fcbaee9e808b729e92948d38d52e5add || >=5.15.145 <5.16 || >=6.1.34 <6.2 || >=6.3.8 <6.4 | b62c510f59803f82f9b4c76ead2a56833b2984c7, cfc0b8e5080aec87700774e8568765eaa4b7b92b, 5.16, 6.2, 6.4 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 12, 2026
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate minimum PDU size for transform requests The receive path applies the minimum SMB2 PDU size check only when ProtocolId is SMB2_PROTO_NUMBER. A packet carrying SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated dialect does not provide transform handling. On an SMB 2.1 connection, a short transform packet therefore reaches init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header and reads beyond the request allocation. The copied fields can then be returned to the unauthenticated client. Compression transforms are converted to ordinary SMB2 messages before protocol validation. After that conversion, validate ordinary SMB2 requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption transform requests to contain both a transform header and an SMB2 header. This rejects truncated requests before work allocation.
Quoted source text, attributed separately from HOL analysis.