Security readout for executives and security teams
Plain-English summary
A race condition in the Linux kernel's Multipath TCP address-management code can cause kernel crashes. The supplied CVSS score is 7.8 and requires local, low-privileged access, so this is primarily a host-compromise and availability concern rather than a remotely exploitable internet threat.
Executive priority
Treat as a high-priority kernel update for multi-user, container-hosting, and other locally exposed systems. Internet-only servers without untrusted local access have lower immediate exploitability, but kernel crashes can still create operational disruption. Use vendor package guidance because the bundle does not map every affected release to a corrected version.
Technical view
The flaw occurs in mptcp_pm_nl_flush_addrs_doit(), where list_splice_init() is not safe for RCU readers. Concurrent access can trigger crashes in mptcp_pm_nl_get_local_id() or mptcp_pm_nl_is_backup(). The CVSS vector reports local access, low complexity, low privileges, no user interaction, unchanged scope, and high confidentiality, integrity, and availability impacts.
Likely exposure
Potential exposure includes systems running the listed affected Linux kernel versions from 5.11 through 6.19. Practical reachability likely depends on access to the affected MPTCP network-management path. The bundle does not establish whether MPTCP configuration, namespace permissions, or specific capabilities are required, so administrators should confirm exposure with their distribution.
Exploitation context
The issue was found through syzbot crash testing, and a reproducer was provided to kernel developers. The supplied record says it is not in KEV and contains no evidence of active exploitation. Although the CVSS vector claims high confidentiality, integrity, and availability impacts, the technical description specifically documents crashes and does not describe demonstrated privilege escalation.
Researcher notes
The root cause is an RCU-unsafe list splice during address flushing while concurrent readers inspect MPTCP address state. Multiple stable-tree commits are supplied, indicating branch-specific backports. Exact triggering permissions, affected configuration prerequisites, and exploitation beyond crashes are not established in the bundle and should not be assumed.
Mitigation direction
- Install a vendor-supported kernel containing the applicable stable fix commit.
- Consult the Linux distribution's advisory for exact affected and corrected package versions.
- Prioritize shared or multi-user hosts where untrusted local users can access kernel networking features.
- If patching is delayed, review vendor guidance for safely restricting unnecessary MPTCP functionality.
Validation and detection
- Inventory running kernel versions and compare them with distribution-specific advisories.
- Confirm whether MPTCP is enabled or used on affected systems.
- Verify the installed kernel includes the applicable stable fix or vendor backport.
- Review kernel logs and crash reports for faults involving the named MPTCP functions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2026-23169 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/338d40bab283da2639780ee3e458fb61f1567d8cCVE reference, Linux
- https://git.kernel.org/stable/c/7896dbe990d56d5bb8097863b2645355633665ebCVE reference, Linux
- https://git.kernel.org/stable/c/455e882192c9833f176f3fbbbb2f036b6c5bf555CVE reference, Linux
- https://git.kernel.org/stable/c/51223bdd0f60b06cfc7f25885c4d4be917adba94CVE reference, Linux
- https://git.kernel.org/stable/c/1f1b9523527df02685dde603f20ff6e603d8e4a1CVE reference, Linux
- https://git.kernel.org/stable/c/e2a9eeb69f7d4ca4cf4c70463af77664fdb6ab1dCVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.