Quick answers
- Is CVE-2026-99180 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-99180 being exploited in the wild.
- How severe is CVE-2026-99180?
- Informational severity, published 28 October 2026.
- Which products and versions are affected?
- Linux Kernel Versions with CONFIG_UNICODE enabled using case-insensitive filename handling.
- Is there a fix for CVE-2026-99180?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-99180 attacked?
- It is attacked with local access.
- Am I affected by CVE-2026-99180?
- 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 occurs in generic_ci_d_hash() and generic_ci_d_compare() functions which dereference the Unicode map (sb->s_encoding) under RCU read lock. When a filesystem is unmounted via ->put_super(), the map is freed immediately even if an in-progress pathwalk is still reading it, causing a use-after-free. The fix delays map deallocation until after an RCU grace period expires, ensuring any active pathwalks complete before the memory is freed.</details> <parameter name="affected_kind">os
Affected products
- Linux kernel Versions with CONFIG_UNICODE enabled using case-insensitive filename handling
Timeline
- 2026-10-28: disclosed