alpha: fix user-space corruption during memory compaction
CVE-2026-43258 · published 6 May 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-43258?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: a48d07afdf18212de22b959715b16793c5a6e57a to < 5593c9b255ae73f57a8b5e696a660032acbd67da, a48d07afdf18212de22b959715b16793c5a6e57a to < d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6, a48d07afdf18212de22b959715b16793c5a6e57a to < 03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f, a48d07afdf18212de22b959715b16793c5a6e57a to < bab8d762a8dbb816b10011e13b87d1bca91e5f77
- Linux Linux: 2.6.16
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
alpha: fix user-space corruption during memory compaction
Alpha systems can suffer sporadic user-space crashes and heap
corruption when memory compaction is enabled.
Symptoms include SIGSEGV, glibc allocator failures (e.g. "unaligned
tcache chunk"), and compiler internal errors. The failures disappear
when compaction is disabled or when using global TLB invalidation.
The root cause is insufficient TLB shootdown during page migration.
Alpha relies on ASN-based MM context rollover for instruction cache
coherency, but this alone is not sufficient to prevent stale data or
instruction translations from surviving migration.
Fix this by introducing a migration-specific helper that combines:
- MM context invalidation (ASN rollover),
- immediate per-CPU TLB invalidation (TBI),
- synchronous cross-CPU shootdown when required.
The helper is used only by migration/compaction paths to avoid changing
global TLB semantics.
Additionally, update flush_tlb_other(), pte_clear(), to use
READ_ONCE()/WRITE_ONCE() for correct SMP memory ordering.
This fixes observed crashes on both UP and SMP Alpha systems.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/5593c9b255ae73f57a8b5e696a660032acbd67da
- git.kernel.org/stable/c/d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6
- git.kernel.org/stable/c/03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f
- git.kernel.org/stable/c/bab8d762a8dbb816b10011e13b87d1bca91e5f77
- git.kernel.org/stable/c/dd5712f3379cfe760267cdd28ff957d9ab4e51c7
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON