CVE-2026-68472

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: validate EHT MLE before MLD ID read

cfg80211_gen_new_ie() copies ML probe response elements from the parent frame when the parent EHT multi-link element has an MLD ID matching the nontransmitted BSSID index.

The code only checked that the extension element had more than one byte before calling ieee80211_mle_get_mld_id(). That helper assumes a BASIC MLE with enough common info and documents that callers must first use ieee80211_mle_type_ok().

Attack chain: malicious AP sends a short EHT MLE in an MBSSID beacon. cfg80211_inform_bss_frame_data() stores the copied IE buffer. cfg80211_parse_mbssid_data() builds the nontransmitted BSS IE. cfg80211_gen_new_ie() sees the EHT MLE in the parent frame. ieee80211_mle_get_mld_id() then reads past the IE boundary.

Validate the MLE type and size before reading the MLD ID. This matches the contract required by the MLE helper and rejects the short element before any internal MLE fields are accessed.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/3b0505e43da8fb5b2a7994c3c3604e5a74692154
• https://git.kernel.org/stable/c/584657c5fc58d7a840623a2fa06331c9661dd0f1
• https://git.kernel.org/stable/c/74e27cd1d98b546fdb276008a83708d062339661