CVE-2019-20422 Null dereference in n/a

What is CVE-2019-20422?

CVE-2019-20422 is a medium-severity vulnerability in Linux kernel, published on 27 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel before 5.3.4, fib6_rule_lookup in net/ipv6/ip6_fib.c mishandles the RT6_LOOKUP_F_DST_NOREF flag in a reference-count decision, leading to (for example) a crash that was identified by syzkaller, aka CID-7b09c2d052db.

Weakness: CWE-755

Which versions are affected by CVE-2019-20422?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2019-20422?

Apply the vendor's patch.

Is CVE-2019-20422 being exploited?

There is no known exploitation of CVE-2019-20422 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-mgr5-cghm-p294, UBUNTU-CVE-2019-20422.