How severe is CVE-2026-72126?

No CVSS score has been assigned to CVE-2026-72126 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-72126?

CVE-2026-72126 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-72126?

Update Kernel to 5.10.261 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72126 is resolved across your whole dependency graph.

How do I detect CVE-2026-72126 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-2026-72126 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-2026-72126?

O3 pinpoints whether CVE-2026-72126 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-2026-72126 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-72126 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-2026-72126 published, and has it been updated?

CVE-2026-72126 was published on August 15, 2026 and was last updated on August 16, 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

CVE-2026-72126

CVE-2026-72126 is a security vulnerability in Kernel. O3 Security confirms whether CVE-2026-72126 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

can: isotp: use unconditional synchronize_rcu() in isotp_release()

Published

Aug 15, 2026

Updated

Aug 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 16, 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:

can: isotp: use unconditional synchronize_rcu() in isotp_release()

isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister() and clears so->bound without waiting for a grace period. isotp_release() uses so->bound to decide whether it needs to call synchronize_rcu() before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it skips that synchronize_rcu() and can cancel the timer while an in-flight isotp_rcv() is still executing and about to re-arm it via isotp_send_fc(), leading to a use-after-free timer callback on the freed socket.

sakisho-bot remarked a problem with rtnl_lock held in isotp_notify(), therefore make isotp_release() always call synchronize_rcu() before cancelling the timers, regardless of so->bound. This still closes the original race (isotp_notify() clearing so->bound without waiting for in-flight isotp_rcv() callers before isotp_release() cancels the RX timer) without adding any RCU wait to the netdevice notifier path.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 5.11.0&&< 5.10.261	5.10.261

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 5.10.261 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72126 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-2026-72126 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-2026-72126. 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: can: isotp: use unconditional synchronize_rcu() in isotp_release() isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister() and clears so->bound without waiting for a grace period. isotp_release() uses so->bound to decide whether it needs to call synchronize_rcu() before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it skips that synchronize_rcu() and can cancel the timer while an in-flight isotp_rcv() is still executing and about to re-arm it via isotp_send_fc(), leading to a use-after-free ti

O3 Security · Impact-Aware SCA

Is CVE-2026-72126 in your dependencies?

O3 detects CVE-2026-72126 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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