In the Linux kernel, the following vulnerability has been resolved: bpf: Support for hardening against JIT spraying The BPF JIT allocator packs many… (CVE-2026-64508)
Source GCVE Database
No CVSS score published yet
- Exploitation
Not in CISA KEV, no exploitation reported
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 8% of CVEs
What to do
AI-suggested
A fix has been implemented in the Linux kernel that flushes indirect branch predictors before reusing JIT memory, preventing reuse of stale branch predictions. This fix is architecture-dependent and applies to allocations within certain size bounds. Users should update to a Linux kernel version that includes this patch to ensure protection. Patch status is not explicitly stated in the provided data; therefore, check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply them accordingly.
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Support for hardening against JIT spraying The BPF JIT allocator packs many small programs into larger executable allocations and reuses space within those allocations as programs are loaded and freed. When fresh code is written into space that a previous program occupied, an indirect jump into the new program can reuse a branch prediction left behind by the old one. Flush the indirect branch predictors before reusing JIT memory so that indirect jumps into a newly written program don't reuse predictions from an old program that occupied the same space. Introduce bpf_arch_pred_flush_enabled static key and bpf_arch_pred_flush static call for flushing the branch predictors on JIT memory reuse. Architectures that need a flush, can update it to a predictor flush function. By default, its a NOP and does not emit any CALL. Allocations larger than a pack are not covered by this flush. That is safe because cBPF programs (the unprivileged attack surface) are bounded well below a pack size. Issue a warning if this assumption is ever violated while the flush is active.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64508 (opens in a new tab)
- git.kernel.org/stable/c/6e52c240c43a601b681e3a4e58fc5685114d4726 (opens in a new tab)
- git.kernel.org/stable/c/7a6c171c6a1ac6d1509752dac131d941a3de0b37 (opens in a new tab)
- git.kernel.org/stable/c/8ff183ee4d8c452960df58175a094828c0513b2e (opens in a new tab)
- git.kernel.org/stable/c/96cce16e26dd02a8678f1e87f88a4b5cdb63b995 (opens in a new tab)
- git.kernel.org/stable/c/eed774da601268dae674e14d54a15e3624691f52 (opens in a new tab)