CVE-2026-90043
HIGHCVE-2026-90043 is a high-severity (CVSS 7.8) vulnerability in Kernel. O3 Security confirms whether CVE-2026-90043 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
zram: fix slot lock bit position on big-endian 64-bit
Real-World Exposure
KernelReal-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:
zram: fix slot lock bit position on big-endian 64-bit
The slot lock is a bit operation on the whole __lock word, which flags and ac_time alias as two u32s. On little-endian the lock bit lands in the position ZRAM_ENTRY_LOCK reserves in flags, so the aliasing works out. On 64-bit big-endian it lands in ac_time instead: with ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time from mark_slot_accessed() or slot_free() wipes out the held lock bit, letting another CPU take the same slot lock; an access time value with that bit set makes the slot look locked forever.
Shift the lock bit into the flags half of the word on big-endian 64-bit.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 7.0.0&&< 7.2.5 | 7.2.5 |
Detection & mitigation playbook
Open-source dependencyDetect
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 7.2.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90043 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-2026-90043 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-2026-90043. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-90043 in your dependencies?
O3 detects CVE-2026-90043 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.