Linux Kernel up to 7.1.4 BPF Wrappers opts__sz allocation of resources

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.1.4 and classified as very critical. The impacted element is the function Wrappers of the component BPF. Executing a manipulation of the argument opts__sz can lead to allocation of resources. The identification of this vulnerability is CVE-2026-72423. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.1.4. This vulnerability affects the function Wrappers of the component BPF. The manipulation of the argument opts__sz with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf: Guard conntrack opts error writes The conntrack lookup and allocation kfuncs take an opts pointer together with an opts__sz argument. The verifier checks only the memory range described by opts__sz, but the wrappers unconditionally write opts->error whenever the internal lookup or allocation helper returns an error. For an invalid size smaller than the end of opts->error, that write can land outside the verifier-checked range. Keep returning NULL for invalid arguments, but only report the error through opts->error when the supplied size includes the field. This preserves error reporting for the supported 12-byte and 16-byte layouts, and for other invalid sizes that still include opts->error.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-72423 since 08/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/15/2026). The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 7.1.5 or 7.2-rc1 eliminates this vulnerability. Applying the patch dd74c80203842a21b2ebb9f70d1260d9aa20fa05/6f6183a39533d727deaa5061cadae6dd9e6744d0 is able to eliminate this problem.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion