From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-74287][MODERATE 7.0] sctp: validate embedded address parameter length [ Upstream Date: Sat, 15 Aug 2026 05:23:36 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-74287 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: 4 X-AL-KERNEL-Commit: 06c8bf48505f2fef265931db82d5003d302a347b List-Id: CVE: CVE-2026-74287 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: sctp: validate embedded address parameter length [ Upstream Commit: 06c8bf48505f2fef265931db82d5003d302a347b Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=06c8bf48505f2fef265931db82d5003d302a347b Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74287 Analysis date: Sat, 15 Aug 2026 05:23:36 -0400 ActionableScore: 5 ActionableScore lower bound: 4 Actionable bucket: Actionable Moderate at minimum Manual review required: YES Summary: A remote out-of-bounds read in SCTP ADD_IP, DEL_IP, and SET_PRIMARY embedded address parameter parsing can be triggered by malformed INIT or ASCONF traffic, with likely impact of remote DoS and limited confidentiality concern but no demonstrated write or privilege-escalation primitive. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74287 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74287 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 7.0 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-2026-74287 MODERATE CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H';CWE-125;CWE-130;*CWE-20;Other CVSS 'AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L';BEST CVSS score: '8.2';DESCR 'An out-of-bounds read in SCTP ADD_IP, DEL_IP, and SET_PRIMARY address parameter parsing can occur because the embedded address parameter length was not checked against the enclosing parameter bounds. A malformed peer can advertise an embedded address length that exceeds the remaining bytes in an INIT or ASCONF parameter, causing later address parsing to read past the validated parameter buffer. For the CVSS the PR:N because a remote peer can send malformed SCTP control data without requiring local access or an authenticated user context. The issue is network reachable on systems that accept SCTP traffic and use the affected INIT or ASCONF processing paths. Impact is mainly remote denial of service and limited confidentiality risk from an out-of-bounds read. Because this is a network reachable kernel parser bug, manual review is recommended.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 5) YES OOB NETWORK LINUS IPV6 KPANIC KPANIC INCREASED_TO_MODERATE7_BASED_ON_GUESSCVSS NO NO checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 ActionableScoreLower=4 ## 1. ActionableScore * Conservative score: 4 * Paranoid score: 5 * Final recommended bucket: **Actionable Moderate at minimum**:: ## 2. Signal breakdown Conservative signals: * Remote reachable / network-triggerable: +2 Malformed SCTP INIT or ASCONF parameters can be supplied by a remote peer on systems accepting SCTP traffic. * Confidentiality impact plausible: +1 The patch explicitly prevents an out-of-bounds read in kernel SCTP parameter parsing. This supports limited confidentiality concern, but not a proven disclosure primitive. * Common protocol receive / packet-processing path: +1 The affected code is in SCTP control-parameter parsing during protocol processing, not a local-only ioctl or admin-only control path. Paranoid additional signal: * Reliable kernel crash / strong DoS: +1 A network-triggered kernel out-of-bounds read in a protocol parser can plausibly lead to kernel fault or crash depending on skb layout and hardening, even though the patch does not show an OOB write or arbitrary corruption primitive. Not awarded: * No privilege escalation plausible bonus. The patch shows OOB read, not UAF reclaim, OOB write, refcount takeover, callback control, or type confusion. * No generic strong memory corruption bonus. This is read-only OOB parsing, not a demonstrated write or lifetime corruption primitive. * No integrity impact. The patch does not support attacker-controlled modification of kernel data or protocol state beyond malformed input rejection. ## 3. Reachability analysis A remote peer can trigger the vulnerable path by sending malformed SCTP ADD_IP, DEL_IP, or SET_PRIMARY address parameters where the embedded address parameter length exceeds the enclosing parameter bounds. The INIT path is especially relevant because it can occur early in association setup. ASCONF reachability depends on SCTP dynamic address reconfiguration being used and accepted. No local privileges are required if the target accepts SCTP traffic from the attacker, so the practical PR interpretation is PR:N. Containers and namespaces do not materially reduce the network-triggered nature unless SCTP exposure is blocked by firewalling or module policy. SCTP is less commonly exposed than TCP or UDP services, but this is still a remotely reachable kernel network parser path when SCTP is enabled and reachable. ## 4. Severity interpretation This behaves like an actionable Moderate issue, not an ordinary auto-closable Moderate. The realistic primitive is a remote out-of-bounds read with possible kernel crash and limited confidentiality concern. It does not currently justify Important-class treatment because there is no OOB write, UAF, reclaim primitive, type confusion, or demonstrated privilege-escalation path. The paranoid score is raised because remote kernel protocol parser bugs historically deserve manual review, especially when malformed peer-controlled lengths cross validated buffer boundaries. ## 5. One-sentence report phrase A remote out-of-bounds read in SCTP ADD_IP, DEL_IP, and SET_PRIMARY embedded address parameter parsing can be triggered by malformed INIT or ASCONF traffic, with likely impact of remote DoS and limited confidentiality concern but no demonstrated write or privilege-escalation primitive. ## 6. Manual review recommendation MANUAL CHECK REQUIRED Reason: this is a network-reachable PR:N kernel protocol parser OOB read, so it should not be auto-closed even though the demonstrated primitive is limited and does not show strong memory corruption or LPE. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: sctp: validate embedded address parameter length [ Upstream Commit: 06c8bf48505f2fef265931db82d5003d302a347b Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=06c8bf48505f2fef265931db82d5003d302a347b Changed files: net/sctp/sm_make_chunk.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=06c8bf48505f2fef265931db82d5003d302a347b ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-74287 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-74287 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:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L The Best / paranoid CVSS vector: AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H The Best / paranoid CVSS score: 8.2 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: 4 Paranoid ActionableScore: 5 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: YES Published priority for this report (same as in Subject): MODERATE 7.0 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).