CVE-2026-72019: Linux kernel · macsec: don't read an unset MAC header in macsec_encrypt()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The vulnerability has been resolved in updated linux-azure kernel versions by changing the code to use skb_eth_hdr() instead of eth_hdr(). Users should apply the official linux-azure kernel updates that include this fix to mitigate the issue.
Description
A vulnerability in the Linux kernel's macsec_encrypt() function in the linux-azure kernel versions causes a 12-byte heap out-of-bounds read when the MAC header is unset during packet transmission. This flaw results in reading memory out of bounds and leaking it on the network frame's outer source/destination MAC address. The issue has been resolved by modifying the code to safely access the L2 header using skb_eth_hdr() instead of eth_hdr().
References
- nvd.nist.gov/vuln/detail/CVE-2026-72019 (opens in a new tab)
- git.kernel.org/stable/c/2cf10d042562283ff4ae97c02d0993d4f1b5ea29 (opens in a new tab)
- git.kernel.org/stable/c/c39087ad0b97fc11a3b058dfc8db9fd370762cb9 (opens in a new tab)
- git.kernel.org/stable/c/dc9ffa1905e72f026d080880a2e4cfc42aa91000 (opens in a new tab)
- git.kernel.org/stable/c/e17a42199824973cd8212e95b21ffadf4114a21b (opens in a new tab)
- git.kernel.org/stable/c/f21fa533a3ed15ada74106aac4b9ddd078fc6b7a (opens in a new tab)
- git.kernel.org/stable/c/f5089008f90c0a7c5520dff3934e0af00adf322d (opens in a new tab)
- ubuntu.com/security/CVE-2026-72019 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72019 (opens in a new tab)
- git.kernel.org/linus/f5089008f90c0a7c5520dff3934e0af00adf322d (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)