CVE-2026-23279
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix NULL pointer dereference in mesh_rx_csa_frame() In mesh_rx_csa_frame(), elems->mesh_chansw_params_ie is dereferenced at lines 1638 and 1642 without a prior NULL…
Does this matter?
Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix NULL pointer dereference in mesh_rx_csa_frame() In mesh_rx_csa_frame(), elems->mesh_chansw_params_ie is dereferenced at lines 1638 and 1642 without a prior NULL check: ifmsh->chsw_ttl = elems->mesh_chansw_params_ie->mesh_ttl; ... pre_value = le16_to_cpu(elems->mesh_chansw_params_ie->mesh_pre_value); The mesh_matches_local() check above only validates the Mesh ID, Mesh Configuration, and Supported Rates IEs. It does not verify the presence of the Mesh Channel Switch Parameters IE (element ID 118). When a received CSA action frame omits that IE, ieee802_11_parse_elems() leaves elems->mesh_chansw_params_ie as NULL, and the unconditional dereference causes a kernel NULL pointer dereference. A remote mesh peer with an established peer link (PLINK_ESTAB) can trigger this by sending a crafted SPECTRUM_MGMT/CHL_SWITCH action frame that includes a matching Mesh ID and Mesh Configuration IE but omits the Mesh Channel Switch Parameters IE. No authentication beyond the default open mesh peering is required. Crash confirmed on kernel 6.17.0-5-generic via mac80211_hwsim: BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:ieee80211_mesh_rx_queued_mgmt+0x143/0x2a0 [mac80211] CR2: 0000000000000000 Fix by adding a NULL check for mesh_chansw_params_ie after mesh_matches_local() returns, consistent with how other optional IEs are guarded throughout the mesh code. The bug has been present since v3.13 (released 2014-01-19).
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.14% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/017c1792525064a723971f0216e6ef86a8c7af11Patch
- https://git.kernel.org/stable/c/22a9adea7e26d236406edc0ea00b54351dd56b9cPatch
- https://git.kernel.org/stable/c/2b5f282b1b7241ef624c3399a1cdff0bb1a3eeabPatch
- https://git.kernel.org/stable/c/753ad20dcbe36b67088c7770d8fc357d7cc43e08Patch
- https://git.kernel.org/stable/c/be8b82c567fda86f2cbb43b7208825125bb31421Patch
- https://git.kernel.org/stable/c/cc6d5a3c0a854aeae00915fc5386570c86029c60Patch
- https://git.kernel.org/stable/c/f061336f072ab03fd29270ae61fede46bf8fd69dPatch
- https://git.kernel.org/stable/c/f5d8af683410a8c82e48b51291915bd612523d9aPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.