CVE-2026-72423
bpf: Guard conntrack opts error writes
Description
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.
INFO
Published Date :
Aug. 15, 2026, 6:22 a.m.
Last Modified :
Aug. 17, 2026, 6:19 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Apply Linux kernel patches for conntrack handling.
- Verify conntrack options size checks.
- Ensure error reporting is within bounds.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72423.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/6f6183a39533d727deaa5061cadae6dd9e6744d0 | |
| https://git.kernel.org/stable/c/dd74c80203842a21b2ebb9f70d1260d9aa20fa05 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72423 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72423
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72423 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72423 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': 'dd74c80203842a21b2ebb9f70d1260d9aa20fa05', 'versionType': 'git'}, {'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': '6f6183a39533d727deaa5061cadae6dd9e6744d0', 'versionType': 'git'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.18'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.18', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': 'dd74c80203842a21b2ebb9f70d1260d9aa20fa05', 'versionType': 'git'}, {'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': '6f6183a39533d727deaa5061cadae6dd9e6744d0', 'versionType': 'git'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.18'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.18', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': 'dd74c80203842a21b2ebb9f70d1260d9aa20fa05', 'versionType': 'git'}, {'status': 'affected', 'version': 'b4c2b9593a1c4c3a718370e34af28e817fd5e5c6', 'lessThan': '6f6183a39533d727deaa5061cadae6dd9e6744d0', 'versionType': 'git'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.18'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.18', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nf_conntrack_bpf.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/6f6183a39533d727deaa5061cadae6dd9e6744d0 Added Reference https://git.kernel.org/stable/c/dd74c80203842a21b2ebb9f70d1260d9aa20fa05