CVE-2023-53373 crypto: seqiv - Handle EBUSY correctly

What is CVE-2023-53373?

CVE-2023-53373 is a high-severity use after free vulnerability in Linux kernel, published on 18 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

crypto: seqiv - Handle EBUSY correctly

As it is seqiv only handles the special return value of EINPROGERSS, which means that in all other cases it will free data related to the request.

However, as the caller of seqiv may specify MAY_BACKLOG, we also need to expect EBUSY and treat it in the same way. Otherwise backlogged requests will trigger a use-after-free.

Weakness: CWE-416

Which versions are affected by CVE-2023-53373?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-53373?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2023-53373 being exploited?

There is no known exploitation of CVE-2023-53373 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 BELL-CVE-2023-53373, DEBIAN-CVE-2023-53373, GHSA-gxr7-4mfg-37c7, UBUNTU-CVE-2023-53373.