How severe is CVE-2026-80578?

CVE-2026-80578 has a CVSS score of 7.3/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-80578?

CVE-2026-80578 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-80578?

Update Kernel to 6.6.153 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-80578 is resolved across your whole dependency graph.

How do I detect CVE-2026-80578 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-2026-80578 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-2026-80578?

O3 pinpoints whether CVE-2026-80578 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-2026-80578 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-80578 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-2026-80578 published, and has it been updated?

CVE-2026-80578 was published on August 26, 2026 and was last updated on August 28, 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-2026-80578

HIGH

CVE-2026-80578 is a high-severity (CVSS 7.3) vulnerability in Kernel. O3 Security confirms whether CVE-2026-80578 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

fbdev: core: Fix pointer desynchronization in fb_io_read()

Published

Aug 26, 2026

Updated

Aug 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 28, 2026 · OSV.dev, 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:

fbdev: core: Fix pointer desynchronization in fb_io_read()

In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to a faulty user buffer), the loop adjusts the chunk size 'c' and updates the remaining 'count'. However, the hardware 'src' pointer has already been eagerly advanced by the original chunk size.

If the loop is allowed to continue, the read will resume from an incorrect, over-advanced offset. Since the remaining 'count' was only decremented by the successful bytes, this desynchronization causes the next iterations to execute more hardware reads than originally bounded, eventually leading to out-of-bounds I/O reads.

Fix this by breaking out of the loop immediately upon a partial copy_to_user(). A partial copy indicates a faulty user buffer, making subsequent read attempts futile. Breaking out ensures we return the number of successfully read bytes without risking out-of-bounds hardware accesses in subsequent mismatched iterations.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 6.5.0&&< 6.6.153	6.6.153

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 6.6.153 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-80578 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-2026-80578 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-2026-80578. 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: fbdev: core: Fix pointer desynchronization in fb_io_read() In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to a faulty user buffer), the loop adjusts the chunk size 'c' and updates the remaining 'count'. However, the hardware 'src' pointer has already been eagerly advanced by the original chunk size. If the loop is allowed to continue, the read will resume from an incorrect, over-advanced offset. Since the remaining 'count' was only decremented by the successful bytes, this desynchronization causes the

O3 Security · Impact-Aware SCA

Is CVE-2026-80578 in your dependencies?

O3 detects CVE-2026-80578 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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