CVE-2026-64187 Linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: xfs: fail recovery on a committed log item with no regions If the first op of a transaction is a bare transaction header (len == sizeof(struct xfs_trans_header)), xlog_recover_add_to_trans() adds an item but no region, leaving it on r_itemq with ri_cnt == 0 and ri_buf == NULL. The header can be split across op records, so later ops may still add regions; the item is only invalid if the transaction commits with none. The runtime commit path never emits such a transaction, so this only happens on a crafted log. It came from an AI-assisted code audit of the recovery parser. xlog_recover_reorder_trans() calls ITEM_TYPE() on the item, which reads *(unsigned short *)item->ri_buf[0].iov_base and faults on the NULL ri_buf. Reject it there, before the commit handlers that also read ri_buf[0]. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:xlog_recover_reorder_trans (fs/xfs/xfs_log_recover.c:1836) xlog_recover_commit_trans (fs/xfs/xfs_log_recover.c:2043) xlog_recover_process_data (fs/xfs/xfs_log_recover.c:2501) xlog_do_recovery_pass (fs/xfs/xfs_log_recover.c:3244) xlog_recover (fs/xfs/xfs_log_recover.c:3493) xfs_log_mount (fs/xfs/xfs_log.c:618) xfs_mountfs (fs/xfs/xfs_mount.c:1034) xfs_fs_fill_super (fs/xfs/xfs_super.c:1938) vfs_get_tree (fs/super.c:1695) path_mount (fs/namespace.c:4161) __x64_sys_mount (fs/namespace.c:4367)
Browse Linux security risksQuick answer
Linux should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- < d50b1fd066d66ceb548ba43e332cfe8a47e5e55a
- < d98f22d2e11e0a36493aeb25b2933571ee90d9a4
- < cccbabeb9a18fcb978d76d6047f2b59214aa7749
- < 2094dab19d45c487285617b7b68913d0cc0c1211
- 4.3
Fixed versions
- 6.12.96
- 6.18.39
- 7.1.4
- 7.2-rc4
How to fix it
CVE-2026-64187 affects Linux and involves denial of service. A remote or untrusted peer may consume excessive resources or crash the affected service. Prioritize deployments that process untrusted input, expose the affected feature, or hold sensitive data. Upgrade Linux to 6.12.96, 6.18.39, 7.1.4, 7.2-rc4 or a later vendor-supported fixed release.
- Inventory every deployment, device, package, plugin, container, build, and environment that uses Linux.
- Compare the installed version with the recorded affected range: < d50b1fd066d66ceb548ba43e332cfe8a47e5e55a, < d98f22d2e11e0a36493aeb25b2933571ee90d9a4, < cccbabeb9a18fcb978d76d6047f2b59214aa7749, < 2094dab19d45c487285617b7b68913d0cc0c1211, 4.3.
- Upgrade Linux to 6.12.96, 6.18.39, 7.1.4, 7.2-rc4 or a later vendor-supported fixed release.
- Until patched, limit untrusted files and peers, apply resource limits, and isolate the affected parser or service.
- Review configuration, roles, tokens, network paths, and exposed endpoints connected to Linux; remove access that is not required.
- Review application, system, proxy, and audit logs for requests and behavior linked to the affected feature and CVE.
- If exploitation is suspected, isolate affected assets, preserve evidence, rotate exposed credentials or keys, restore trusted data, and rebuild compromised systems before returning them to service.
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Verify the fix
- Confirm every affected asset now runs the fixed vendor-supported release or has the documented mitigation for CVE-2026-64187 in place.
- Use a safe regression test to confirm the affected denial of service path no longer produces the vulnerable behavior.
- Confirm temporary access controls, endpoint restrictions, network blocks, and least-privilege settings remain effective after the update.
- Review post-remediation logs and rerun Fixnx plus the relevant package, dependency, firmware, browser, or product-specific security check.
- Document affected assets, versions, changes, validation evidence, reviewed logs, and any credential rotation, cleanup, or replacement completed.
Related categories
Related security risks
More published guidance from the same primary category.
Trusted references
FAQ
What is affected by CVE-2026-64187?
Linux versions listed as affected should be reviewed: < d50b1fd066d66ceb548ba43e332cfe8a47e5e55a, < d98f22d2e11e0a36493aeb25b2933571ee90d9a4, < cccbabeb9a18fcb978d76d6047f2b59214aa7749, < 2094dab19d45c487285617b7b68913d0cc0c1211, 4.3.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.