How severe is CVE-2026-74343?

CVE-2026-74343 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-74343?

CVE-2026-74343 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-74343?

Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-74343 is resolved across your whole dependency graph.

How do I detect CVE-2026-74343 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-74343 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-74343?

O3 pinpoints whether CVE-2026-74343 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-74343 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-74343 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-74343 published, and has it been updated?

CVE-2026-74343 was published on August 15, 2026 and was last updated on August 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐧

🐧 Linux

Not in CISA KEV

HIGH severity

CVE-2026-74343

HIGH

CVE-2026-74343 is a high-severity (CVSS 7.8) vulnerability in Kernel. O3 Security confirms whether CVE-2026-74343 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

kernfs: fix xattr race condition with multiple superblocks

Published

Aug 15, 2026

Updated

Aug 18, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

In the Linux kernel, the following vulnerability has been resolved:

kernfs: fix xattr race condition with multiple superblocks

Multiple superblocks with different namespaces can share the same kernfs_node when kernfs_test_super() finds a matching root but different namespace. This means multiple inodes from different superblocks can reference the same kernfs_node->iattr->xattrs structure.

The VFS layer only holds per-inode locks during xattr operations, which is insufficient to serialize concurrent xattr modifications on the shared kernfs_node. This can lead to race conditions in simple_xattr_set() where the lookup->replace/remove sequence is not atomic with respect to operations from other superblocks.

Fix this by protecting xattr operations with the existing hashed kernfs_locks->open_file_mutex[] array, which is already used to protect per-node open file data. The hashed mutex array provides scalable per-node serialization (scaled by CPU count, up to 1024 locks on 32+ CPU systems) with zero memory overhead.

Changes:

Rename open_file_mutex[] to node_mutex[] to reflect dual purpose
Add kernfs_node_lock_ptr() and kernfs_node_lock() helpers
Protect simple_xattr_set() calls in kernfs_xattr_set() and kernfs_vfs_user_xattr_set() with the hashed mutex
Update file.c to use new helpers via compatibility wrappers
Update documentation to explain the extended lock usage

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 7.1.0&&< 7.1.5	7.1.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-74343 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-74343 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-74343. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: kernfs: fix xattr race condition with multiple superblocks Multiple superblocks with different namespaces can share the same kernfs_node when kernfs_test_super() finds a matching root but different namespace. This means multiple inodes from different superblocks can reference the same kernfs_node->iattr->xattrs structure. The VFS layer only holds per-inode locks during xattr operations, which is insufficient to serialize concurrent xattr modifications on the shared kernfs_node. This can lead to race conditions in simple_xat

O3 Security · Impact-Aware SCA

Is CVE-2026-74343 in your dependencies?

O3 detects CVE-2026-74343 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works