Quick answers
- Is CVE-2026-99177 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-99177 being exploited in the wild.
- How severe is CVE-2026-99177?
- Informational severity, published 28 October 2026.
- Which products and versions are affected?
- Linux kernel versions with commit 97cd21d57e9b and later, prior to fix.
- Is there a fix for CVE-2026-99177?
- A patch was published on 2026-09-30. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-99177 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-99177?
- Check whether you run Linux kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a missing lock in the sev_gmem_post_populate() function in arch/x86/kvm/svm/sev.c. The code calls set_page_dirty() on a page obtained from get_user_pages_fast() without holding required locks, violating the API contract that the page mapping must remain stable. The fix replaces set_page_dirty() with set_page_dirty_lock() to properly serialize access and prevent concurrent mapping removal.
Affected products
- Linux kernel versions with commit 97cd21d57e9b and later, prior to fix
Timeline
- 2026-10-28: disclosed
- 2026-09-30: patched