CVE-2026-74668
packet: use consistent hard_header_len in TX_RING send path
Description
In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in TX_RING send path tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 27, 2026, 1:18 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
- Apply the Linux kernel patch.
- Ensure consistent use of hard_header_len.
- Snapshot header length before processing ring frames.
- Update tpacket_fill_skb() with the snapshot.
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-2026-74668.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74668 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-2026-74668
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-2026-74668 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74668 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.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 27, 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-2026-74668.json">CVE-2026-74668</a> Added Reference https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7 Added Reference https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b Added Reference https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc Added Reference https://git.kernel.org/stable/c/2a73b2c37ee3060a880b53cd24783d93fc7be5f8 Added Reference https://git.kernel.org/stable/c/9c7e8ff48c377bef18c3d178748aea0575b69ede Added Reference https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a Added Reference https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd Added Reference https://git.kernel.org/stable/c/e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2 Removed Reference https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7 Removed Reference https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b Removed Reference https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc Removed Reference https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a Removed Reference https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 25, 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 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 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': '69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1', 'lessThan': 'd85d2fd54e901637c81d847811e03c662aee13cd', 'versionType': 'git'}, {'status': 'affected', 'version': '69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1', 'lessThan': '016763e829cac37b3234eace86fd0a4c560de4a7', 'versionType': 'git'}, {'status': 'affected', 'version': '69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1', 'lessThan': '27e068d1b35dbec10a3cf268887c94407be4badc', 'versionType': 'git'}, {'status': 'affected', 'version': '69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1', 'lessThan': 'd48ea5c9c4c34dc0df621f0e39ed3a16b644621a', 'versionType': 'git'}, {'status': 'affected', 'version': '69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1', 'lessThan': '21b5953e7494c16a42e6cd8cf110e18d13ae4a6b', 'versionType': 'git'}], 'programFiles': ['net/packet/af_packet.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2.6.31'}, {'status': 'unaffected', 'version': '0', 'lessThan': '2.6.31', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/packet/af_packet.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in TX_RING send path tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here. Added Reference https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7 Added Reference https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b Added Reference https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc Added Reference https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a Added Reference https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd