CVE-2026-74371
bpf: fix BPF_PROG_QUERY OOB write and cgroup backward compat
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: fix BPF_PROG_QUERY OOB write and cgroup backward compat BPF_PROG_QUERY writes back the 'query.revision' field unconditionally to userspace. If userspace passes a smaller 'bpf_attr' structure (e.g. 40 bytes, which was the layout before the addition of 'query.revision'), the kernel performs an out-of-bounds write. Fix this by propagating the user-provided attribute size 'uattr_size' down to the cgroup query handlers, and conditionally skipping writing the revision field to userspace when the provided buffer size is insufficient. query.revision in bpf_mprog_query is structurally identical to the cgroup case: a late tail field, written unconditionally. But the backward-compat hazard is not the same. The min-historical-size test is per command, and bpf_mprog_query only serves attach types that were born with revision in the struct: - tcx_prog_query -> BPF_TCX_INGRESS/EGRESS - netkit_prog_query -> BPF_NETKIT_PRIMARY/PEER tcx, netkit, the revision field, and bpf_mprog_query itself all landed in the same v6.6 merge window (053c8e1f235d added the mprog query API + revision; tcx in e420bed02507, netkit in 35dfaad7188c). There has never been a tcx/netkit BPF_PROG_QUERY userspace that doesn't know about revision. So for these commands the minimum legitimate struct already covers offset 56-64 — no old binary can be broken here. Contrast with cgroup: BPF_PROG_QUERY on cgroup attach types shipped in 2017; revision write-back was bolted on years later (120933984460). That path has a real population of pre-revision callers.
INFO
Published Date :
Aug. 15, 2026, 6:22 a.m.
Last Modified :
Sept. 14, 2026, 12:17 p.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
- Propagate user attribute size to handlers.
- Conditionally skip revision field write.
- Ensure buffer size is sufficient for revision field.
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-2026-74371.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74371 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-2026-74371
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-2026-74371 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74371 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
Sep. 14, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/74xxx/CVE-2026-74371.json">CVE-2026-74371</a> Added Reference https://git.kernel.org/stable/c/21c4b99b27f3f85b89256e81b3e997dec0a460d0 Added Reference https://git.kernel.org/stable/c/a7131340d0f95df9a541257dccab5d85e6bcdd2b Added Reference https://git.kernel.org/stable/c/b78eb6efbf052d44a3a14726aa7c7d5aa2e544d7 Added Reference https://git.kernel.org/stable/c/d3d630e8a7f3421bc2d204b87bdff35b4432a8e3 Removed Reference https://git.kernel.org/stable/c/21c4b99b27f3f85b89256e81b3e997dec0a460d0 Removed Reference https://git.kernel.org/stable/c/a7131340d0f95df9a541257dccab5d85e6bcdd2b Removed Reference https://git.kernel.org/stable/c/d3d630e8a7f3421bc2d204b87bdff35b4432a8e3 -
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:U/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': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'a7131340d0f95df9a541257dccab5d85e6bcdd2b', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'd3d630e8a7f3421bc2d204b87bdff35b4432a8e3', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': '21c4b99b27f3f85b89256e81b3e997dec0a460d0', 'versionType': 'git'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'a7131340d0f95df9a541257dccab5d85e6bcdd2b', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'd3d630e8a7f3421bc2d204b87bdff35b4432a8e3', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': '21c4b99b27f3f85b89256e81b3e997dec0a460d0', 'versionType': 'git'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.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': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'a7131340d0f95df9a541257dccab5d85e6bcdd2b', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': 'd3d630e8a7f3421bc2d204b87bdff35b4432a8e3', 'versionType': 'git'}, {'status': 'affected', 'version': '1209339844601ec1766f4ff430673fbcfe42bb51', 'lessThan': '21c4b99b27f3f85b89256e81b3e997dec0a460d0', 'versionType': 'git'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/linux/bpf-cgroup.h', 'kernel/bpf/cgroup.c', 'kernel/bpf/syscall.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: bpf: fix BPF_PROG_QUERY OOB write and cgroup backward compat BPF_PROG_QUERY writes back the 'query.revision' field unconditionally to userspace. If userspace passes a smaller 'bpf_attr' structure (e.g. 40 bytes, which was the layout before the addition of 'query.revision'), the kernel performs an out-of-bounds write. Fix this by propagating the user-provided attribute size 'uattr_size' down to the cgroup query handlers, and conditionally skipping writing the revision field to userspace when the provided buffer size is insufficient. query.revision in bpf_mprog_query is structurally identical to the cgroup case: a late tail field, written unconditionally. But the backward-compat hazard is not the same. The min-historical-size test is per command, and bpf_mprog_query only serves attach types that were born with revision in the struct: - tcx_prog_query -> BPF_TCX_INGRESS/EGRESS - netkit_prog_query -> BPF_NETKIT_PRIMARY/PEER tcx, netkit, the revision field, and bpf_mprog_query itself all landed in the same v6.6 merge window (053c8e1f235d added the mprog query API + revision; tcx in e420bed02507, netkit in 35dfaad7188c). There has never been a tcx/netkit BPF_PROG_QUERY userspace that doesn't know about revision. So for these commands the minimum legitimate struct already covers offset 56-64 — no old binary can be broken here. Contrast with cgroup: BPF_PROG_QUERY on cgroup attach types shipped in 2017; revision write-back was bolted on years later (120933984460). That path has a real population of pre-revision callers. Added Reference https://git.kernel.org/stable/c/21c4b99b27f3f85b89256e81b3e997dec0a460d0 Added Reference https://git.kernel.org/stable/c/a7131340d0f95df9a541257dccab5d85e6bcdd2b Added Reference https://git.kernel.org/stable/c/d3d630e8a7f3421bc2d204b87bdff35b4432a8e3