How severe is CVE-2026-72217?

CVE-2026-72217 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-72217?

CVE-2026-72217 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-72217?

Update Kernel to 6.6.145 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72217 is resolved across your whole dependency graph.

How do I detect CVE-2026-72217 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-2026-72217 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-2026-72217?

O3 pinpoints whether CVE-2026-72217 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-2026-72217 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-72217 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-2026-72217 published, and has it been updated?

CVE-2026-72217 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

CRITICAL severity

CVE-2026-72217

CRITICAL

CVE-2026-72217 is a critical-severity (CVSS 9.8) remote code execution vulnerability in Kernel. O3 Security confirms whether CVE-2026-72217 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

SUNRPC: Bound-check xdr_buf_to_bvec() stores before writing

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:

SUNRPC: Bound-check xdr_buf_to_bvec() stores before writing

xdr_buf_to_bvec() writes a bio_vec into the caller's array before testing whether that slot is in range, and the head branch performs the store with no check at all. When the caller's budget is exactly used up, the next store lands one element past the end of the array. The overflow label returns count - 1, which masks the surplus store but cannot undo it.

rq_bvec, the array passed by nfsd_vfs_write(), is allocated to exactly rq_maxpages entries with no slack. The OOB store can land in adjacent slab memory; the bv_len and bv_offset fields written there are derived from client-supplied RPC payload sizes.

Move the in-range check ahead of the store in the head, page-loop, and tail branches. With the check at the top of each sequence, count is incremented only after a successful store, so the overflow label can return count directly.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 6.6.0&&< 6.6.145	6.6.145

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 6.6.145 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72217 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-2026-72217 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-2026-72217. 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: SUNRPC: Bound-check xdr_buf_to_bvec() stores before writing xdr_buf_to_bvec() writes a bio_vec into the caller's array before testing whether that slot is in range, and the head branch performs the store with no check at all. When the caller's budget is exactly used up, the next store lands one element past the end of the array. The overflow label returns count - 1, which masks the surplus store but cannot undo it. rq_bvec, the array passed by nfsd_vfs_write(), is allocated to exactly rq_maxpages entries with no slack. The

O3 Security · Impact-Aware SCA

Is CVE-2026-72217 in your dependencies?

O3 detects CVE-2026-72217 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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