CVE-2026-72019
macsec: don't read an unset MAC header in macsec_encrypt()
Description
In the Linux kernel, the following vulnerability has been resolved: macsec: don't read an unset MAC header in macsec_encrypt() macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG. On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header(). On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose.
INFO
Published Date :
Aug. 15, 2026, 6:21 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 to a patched version.
- Ensure macsec module is configured correctly.
- Verify header handling in macsec_encrypt().
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-2026-72019.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72019 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-2026-72019
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-2026-72019 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72019 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:L/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': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'dc9ffa1905e72f026d080880a2e4cfc42aa91000', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f21fa533a3ed15ada74106aac4b9ddd078fc6b7a', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'e17a42199824973cd8212e95b21ffadf4114a21b', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': '2cf10d042562283ff4ae97c02d0993d4f1b5ea29', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'c39087ad0b97fc11a3b058dfc8db9fd370762cb9', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f5089008f90c0a7c5520dff3934e0af00adf322d', 'versionType': 'git'}], 'programFiles': ['drivers/net/macsec.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'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-rc3', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/net/macsec.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'dc9ffa1905e72f026d080880a2e4cfc42aa91000', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f21fa533a3ed15ada74106aac4b9ddd078fc6b7a', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'e17a42199824973cd8212e95b21ffadf4114a21b', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': '2cf10d042562283ff4ae97c02d0993d4f1b5ea29', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'c39087ad0b97fc11a3b058dfc8db9fd370762cb9', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f5089008f90c0a7c5520dff3934e0af00adf322d', 'versionType': 'git'}], 'programFiles': ['drivers/net/macsec.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'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': ['drivers/net/macsec.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': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'dc9ffa1905e72f026d080880a2e4cfc42aa91000', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f21fa533a3ed15ada74106aac4b9ddd078fc6b7a', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'e17a42199824973cd8212e95b21ffadf4114a21b', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': '2cf10d042562283ff4ae97c02d0993d4f1b5ea29', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'c39087ad0b97fc11a3b058dfc8db9fd370762cb9', 'versionType': 'git'}, {'status': 'affected', 'version': 'c09440f7dcb304002dfced8c0fea289eb25f2da0', 'lessThan': 'f5089008f90c0a7c5520dff3934e0af00adf322d', 'versionType': 'git'}], 'programFiles': ['drivers/net/macsec.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'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-rc3', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/net/macsec.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: macsec: don't read an unset MAC header in macsec_encrypt() macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG. On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header(). On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose. Added Reference https://git.kernel.org/stable/c/2cf10d042562283ff4ae97c02d0993d4f1b5ea29 Added Reference https://git.kernel.org/stable/c/c39087ad0b97fc11a3b058dfc8db9fd370762cb9 Added Reference https://git.kernel.org/stable/c/dc9ffa1905e72f026d080880a2e4cfc42aa91000 Added Reference https://git.kernel.org/stable/c/e17a42199824973cd8212e95b21ffadf4114a21b Added Reference https://git.kernel.org/stable/c/f21fa533a3ed15ada74106aac4b9ddd078fc6b7a Added Reference https://git.kernel.org/stable/c/f5089008f90c0a7c5520dff3934e0af00adf322d