What’s Vulnerable › Vulnerabilities

CVE-2020-36557

• Severity: medium (CVSS 5.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-07-21 · updated 2026-06-17
• Weakness: CWE-362

Description

A race condition in the Linux kernel before 5.6.2 between the VT_DISALLOCATE ioctl and closing/opening of ttys could lead to a use-after-free.

Affected products

• Linux kernel: before 5.6.2 — fixed in 5.6.2

How to fix

Upgrade to a fixed version: Linux kernel 5.6.2. Check the vendor advisory for mitigations.

References

• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.2
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca4463bf8438b403596edd0ec961ca0d4fbe0220
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.2
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca4463bf8438b403596edd0ec961ca0d4fbe0220

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