Quick answers
- Is CVE-2026-99277 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-99277 being exploited in the wild.
- How severe is CVE-2026-99277?
- Informational severity, published 7 November 2026.
- Which products and versions are affected?
- Linux Kernel Multiple kernel versions; patched in stable branches.
- Is there a fix for CVE-2026-99277?
- A patch was published on 2026-10-21. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-99277 attacked?
- It is attacked over the network or with local access, in an operating system.
- Am I affected by CVE-2026-99277?
- 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 use-after-free in ksmbd's session channel management. When ksmbd_session_unregister() removes a session, a concurrent reference holder can keep the session alive while the connection pointer becomes invalid. The fix adds reference counting to connections held by session channels, ensuring connections remain valid until all session references are released. Exploitation requires local or network access to trigger SMB3.1.1 binding or procfs reads concurrently with session expiration.
Affected products
- Linux Linux kernel Multiple kernel versions; patched in stable branches
Timeline
- 2026-11-07: disclosed
- 2026-10-21: patched