From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-53257][MODERATE REGULAR] wifi: cfg80211: enforce HE/EHT cap/oper consistency [ Upstream Date: Thu, 25 Jun 2026 09:05:14 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-53257 X-AL-KERNEL-Priority: MODERATE REGULAR X-AL-KERNEL-Severity: MODERATE REGULAR X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 3 X-AL-KERNEL-ActionableScore-Lower: 1 X-AL-KERNEL-Commit: 0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a List-Id: CVE: CVE-2026-53257 Priority: MODERATE REGULAR AL-KERNEL base severity: MODERATE KPANIC flag: NO Patch: wifi: cfg80211: enforce HE/EHT cap/oper consistency [ Upstream Commit: 0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53257 Analysis date: Thu, 25 Jun 2026 09:05:14 -0400 ActionableScore: 3 ActionableScore lower bound: 1 Actionable bucket: Borderline ordinary Moderate, manual review recommended for delegated CAP_NET_ADMIN environments Manual review required: YES Summary: cfg80211 failed to reject inconsistent HE/EHT AP settings, allowing a local WiFi management user to pass invalid nl80211 configuration into mac80211 and potentially crash the kernel. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53257 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53257 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: MODERATE REGULAR Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-53257 MODERATE CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H';*CWE-20;**CWE-476;CWE-754;Other CVSS 'AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '5.5';DESCR 'cfg80211 did not reject AP settings where HE or EHT capability data was present without the matching operation element. Such inconsistent nl80211 input can reach mac80211 and cause a kernel crash when EHT capability is set but EHT operation data is missing. For the CVSS the PR:L value is used for the paranoid score because CAP_NET_ADMIN may be delegated to a service account, container root, or reduced capability administrator in some deployments. The issue is not directly network reachable and is triggered through local WiFi AP configuration rather than over the air packet traffic. Impact is denial of service via kernel crash, with no supported evidence of confidentiality impact, integrity impact, or privilege escalation.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline ordinary Moderate, manual review recommended for delegated CAP_NET_ADMIN environments (with actual score 2) YES REMOTE DANGER SIMPLEFIX DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH YES NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=3 ActionableScoreLower=1 ## 1. ActionableScore * Conservative score: 1 * Paranoid score: 3 * Final recommended bucket: **Borderline ordinary Moderate, manual review recommended for delegated CAP_NET_ADMIN environments**:: ## 2. Signal breakdown Conservative signals: * Reliable kernel crash / strong DoS: +1. The commit explicitly says mac80211 could crash when `eht_cap` is set without `eht_oper`. * Availability impact realistic: +1. If triggered, the impact is a kernel crash, not only a harmless warning. * Requires admin/root/CAP_NET_ADMIN in typical deployments: -2. Creating or changing AP settings through nl80211 normally requires CAP_NET_ADMIN or equivalent WiFi management privilege. Conservative total: `+1 +1 -2 = 0..1`, rounded to 1 for actionable triage because a kernel crash is explicitly described. Paranoid signals: * Reliable kernel crash / strong DoS: +1. * Availability impact realistic: +1. The crash is host-impacting once the invalid AP configuration reaches mac80211. * Broad/common subsystem exposure: +1. cfg80211/mac80211 are common WiFi kernel subsystems, although the vulnerable path is AP configuration rather than normal packet RX/TX. * No full CAP penalty in delegated environments: 0 instead of -2. CAP_NET_ADMIN may be delegated to a service account, container root, network manager component, or reduced-capability administrator. Paranoid total: `+1 +1 +1 = 3`. Not counted: * No remote/network-triggerable signal. This is local nl80211 control-plane configuration, not over-the-air packet processing. * No generic memory corruption signal. The patch is validation-only and the described downstream effect is crash, not UAF, OOB write, double free, refcount misuse, or type confusion. * No privilege escalation signal. There is no supported LPE primitive. * No confidentiality or integrity impact. No leak, overwrite, or policy bypass is shown. ## 3. Reachability analysis The bug is triggered by providing inconsistent HE/EHT AP configuration through nl80211, specifically capability data without the matching operation element. In normal deployments this requires CAP_NET_ADMIN and access to WiFi AP management operations, so a regular unprivileged local user usually cannot trigger it. Namespaces and containers matter only if WiFi management or CAP_NET_ADMIN is delegated into a less trusted environment. Wireless devices are commonly managed in the host network namespace, so container reachability is not automatic. The path is not remotely reachable through WiFi frames or network packets. Realistic exploitation is a local or delegated-administration DoS against systems where an attacker can configure AP mode parameters. ## 4. Severity interpretation This behaves like an ordinary Moderate DoS in the conservative view. It becomes a borderline actionable Moderate only when CAP_NET_ADMIN or AP management is delegated to a less trusted user or service. Theoretical memory corruption potential is not supported by the patch. The evidence supports an input-validation failure leading to a kernel crash. It does not support privilege escalation, information disclosure, or integrity compromise. ## 5. One-sentence report phrase cfg80211 failed to reject inconsistent HE/EHT AP settings, allowing a local WiFi management user to pass invalid nl80211 configuration into mac80211 and potentially crash the kernel. ## 6. Manual review recommendation MANUAL CHECK RECOMMENDED. Manual review is recommended only to confirm whether affected deployments delegate CAP_NET_ADMIN or WiFi AP control to non-root or semi-trusted users. If AP configuration is restricted to full host administrators, this can be treated as ordinary Moderate / low-actionability DoS. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: wifi: cfg80211: enforce HE/EHT cap/oper consistency [ Upstream Commit: 0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a Changed files: net/wireless/nl80211.c Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0f5e9ddd7e8e7758771a63cdd498a2007dc8da7a ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-53257 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-53257 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H The Best / paranoid CVSS score: 5.5 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: 1 Paranoid ActionableScore: 3 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: MODERATE KPANIC detected for this report: NO Published priority for this report (same as in Subject): MODERATE REGULAR These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).