CVE-2026-68431

CVE CVE-2026-68431EUVD EUVD-2026-57039Published 2026-08-12T00:07:17.000ZLast changed 2026-08-17T05:05:27.000ZCVSS 9.1

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux e9cb7be2fcbaee9e808b729e92948d38d52e5add; patch: 7.1.6; 6.1.34 <6.2; 6.3.8 <6.4; patch: 0; 368ba06881c395f1c9a7ba22203cf8d78b4addc0 <b62c510f59803f82f9b4c76ead2a56833b2984c7; 5.15.145 <5.16; 543c12c2644e772caa6880662c2a852cfdc5a10c; patch: 7.2; df3a4518aee64f21bcafa891105b468413f27431; 6.4; 368ba06881c395f1c9a7ba22203cf8d78b4addc0 <cfc0b8e5080aec87700774e8568765eaa4b7b92b

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.