CVE-2026-5398
Kernel use-after-free bug in the TIOCNOTTY handler
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.
A malicious process can abuse the dangling pointer to grant itself root privileges.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Kernel use-after-free bug in the TIOCNOTTY handler
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.
A malicious process can abuse the dangling pointer to grant itself root privileges.
- Record
CVE-2026-5398- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
EUVDEUVD-2026-24589
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.
A malicious process can abuse the dangling pointer to grant itself root privileges.
- Record
EUVD-2026-24589- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-w9v4-7vpf-w2r4
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing...
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.
A malicious process can abuse the dangling pointer to grant itself root privileges.
- Record
GHSA-w9v4-7vpf-w2r4- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
NVD
The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.
A malicious process can abuse the dangling pointer to grant itself root privileges.
- Record
CVE-2026-5398- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5398 is a high vulnerability (CVSS 8.4) in Freebsd, published April 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 10th percentile. No source names a fixed version.