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CVE-2026-23246 Linux CVE debrief

CVE-2026-23246 is a high-severity Linux kernel Wi-Fi/mac80211 vulnerability published on 2026-03-18 and last modified on 2026-04-02. The issue is a missing bounds check in ieee80211_ml_reconfiguration: link_id is derived from the ML Reconfiguration element and can range from 0 to 15, but the link_removal_timeout[] stack array has only 15 elements. As described in the source record, accepting link_id == 15 can lead to an out-of-bounds stack write. The vulnerability is rated CVSS 8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Vendor
Linux
Product
Unknown
CVSS
HIGH 8.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-18
Original CVE updated
2026-04-02
Advisory published
2026-03-18
Advisory updated
2026-04-02

Who should care

Linux kernel maintainers, distro security teams, embedded device vendors, and operators of systems that use the kernel Wi-Fi/mac80211 stack should prioritize this issue, especially where wireless management frames may be processed in production environments.

Technical summary

The CVE description states that ieee80211_ml_reconfiguration uses link_id from the ML Reconfiguration element control field (control & 0x000f), which can yield values 0 through 15. The target array, link_removal_timeout[], is sized to IEEE80211_MLD_MAX_NUM_LINKS, which is 15. Because index 15 is outside the valid range, the function could perform an out-of-bounds write on stack memory. The source record indicates the fix is to skip subelements with link_id >= IEEE80211_MLD_MAX_NUM_LINKS. The NVD record is marked "Undergoing Analysis."

Defensive priority

High. This is a memory-corruption flaw in a widely deployed kernel networking component, with potential impact to confidentiality, integrity, and availability, and it is reachable via adjacent-wireless attack conditions per the CVSS vector.

Recommended defensive actions

  • Review whether your Linux kernels include the mac80211 ML Reconfiguration code path referenced by the kernel stable commits linked in the source record.
  • Apply the upstream/stable kernel fix that bounds-checks link_id and rejects subelements with link_id >= IEEE80211_MLD_MAX_NUM_LINKS.
  • Prioritize remediation on systems with Wi-Fi enabled, especially laptops, access points, embedded devices, and other wireless-capable Linux systems.
  • Track distribution advisories and kernel update channels for backported fixes, since the public record does not provide affected version ranges.
  • Validate remediation by confirming the presence of the vendor or distribution patch in your deployed kernel builds.

Evidence notes

All substantive claims in this debrief are taken from the supplied CVE record and its official references. The CVE description explicitly says link_id can be 0..15, link_removal_timeout[] has 15 elements, and index 15 is out-of-bounds, resulting in a stack out-of-bounds write. The CVSS vector in the source record is CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. The NVD record status is "Undergoing Analysis." The provided references point to official Linux kernel stable commits, which support the remediation guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-23246 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-23246

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-23246 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-23246

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/162d331d833dc73a3e905a24c44dd33732af1fc5

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/650981e718e68005ca2760a6358134b8a98ebea4

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/bfde158d5d1322c0c2df398a8d1ccce04943be2e

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d58d71c2167601762351962b9604808d3be94400

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/f35ceec54d48e227fa46f8f97fd100a77b8eab15

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.