CVE-2026-68462
bpf: Reject negative const offsets for buffer pointers
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative const offsets for buffer pointers The verifier rejects variable offsets for PTR_TO_TP_BUFFER and PTR_TO_BUF accesses, but it currently accepts a constant negative offset produced by pointer arithmetic. Commit 022ac0750883 ("bpf: use reg->var_off instead of reg->off for pointers") moved constant pointer offsets from reg->off to reg->var_off. However, __check_buffer_access() continued to check only the instruction offset. An access with reg->var_off equal to -8 and an instruction offset of zero therefore passes verification. For writable raw tracepoints, the access end is also calculated from the unsigned reg->var_off.value. An eight-byte access starting at -8 wraps the calculated end to zero, allowing the program to load and attach without increasing max_tp_access. After ensuring that reg->var_off is constant, calculate the effective access start using signed arithmetic and reject it when it is negative. Use the validated start to calculate the access end for both PTR_TO_TP_BUFFER and PTR_TO_BUF.
INFO
Published Date :
Aug. 15, 2026, 6:18 a.m.
Last Modified :
Aug. 17, 2026, 6:17 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
- Update the Linux kernel.
- Apply commit 022ac0750883.
- Validate pointer arithmetic for buffer access.
- Ensure effective access start is not negative.
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-2026-68462.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/314bd592085c0720ef519f6edbc5f41440ff78d4 | |
| https://git.kernel.org/stable/c/fd4cfa8c8f9a17cdec0539334d28754bc1d8a5d9 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-68462 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-2026-68462
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-2026-68462 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-68462 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: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': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': '314bd592085c0720ef519f6edbc5f41440ff78d4', 'versionType': 'git'}, {'status': 'affected', 'version': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': 'fd4cfa8c8f9a17cdec0539334d28754bc1d8a5d9', 'versionType': 'git'}], 'programFiles': ['kernel/bpf/verifier.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc4', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['kernel/bpf/verifier.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': '314bd592085c0720ef519f6edbc5f41440ff78d4', 'versionType': 'git'}, {'status': 'affected', 'version': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': 'fd4cfa8c8f9a17cdec0539334d28754bc1d8a5d9', 'versionType': 'git'}], 'programFiles': ['kernel/bpf/verifier.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.1', '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': ['kernel/bpf/verifier.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': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': '314bd592085c0720ef519f6edbc5f41440ff78d4', 'versionType': 'git'}, {'status': 'affected', 'version': '022ac075088366b62e130da5e1b200bc93a47191', 'lessThan': 'fd4cfa8c8f9a17cdec0539334d28754bc1d8a5d9', 'versionType': 'git'}], 'programFiles': ['kernel/bpf/verifier.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc4', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['kernel/bpf/verifier.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: bpf: Reject negative const offsets for buffer pointers The verifier rejects variable offsets for PTR_TO_TP_BUFFER and PTR_TO_BUF accesses, but it currently accepts a constant negative offset produced by pointer arithmetic. Commit 022ac0750883 ("bpf: use reg->var_off instead of reg->off for pointers") moved constant pointer offsets from reg->off to reg->var_off. However, __check_buffer_access() continued to check only the instruction offset. An access with reg->var_off equal to -8 and an instruction offset of zero therefore passes verification. For writable raw tracepoints, the access end is also calculated from the unsigned reg->var_off.value. An eight-byte access starting at -8 wraps the calculated end to zero, allowing the program to load and attach without increasing max_tp_access. After ensuring that reg->var_off is constant, calculate the effective access start using signed arithmetic and reject it when it is negative. Use the validated start to calculate the access end for both PTR_TO_TP_BUFFER and PTR_TO_BUF. Added Reference https://git.kernel.org/stable/c/314bd592085c0720ef519f6edbc5f41440ff78d4 Added Reference https://git.kernel.org/stable/c/fd4cfa8c8f9a17cdec0539334d28754bc1d8a5d9