CVE-2026-68121
What it is
In the Linux kernel, the following vulnerability has been resolved: pppoe: reload header pointer after dev_hard_header() pppoe_sendmsg() saves a pointer to the PPPoE header before calling dev_hard_header(). Device header callbacks are allowed to reallocate the skb head, invalidating pointers into it. This can happen when a send is blocked in copy_from_user() while the first non-Ethernet port is added to an empty team device. The team's delegated GRE header callback then expands the skb head. PPPoE subsequently writes six bytes through the stale pointer into the freed head. Reload the PPPoE header through the skb's network-header offset after device header creation. pskb_expand_head() updates that offset when it relocates the head.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Received
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-68121.md and follow it. Check whether this project is affected by CVE-2026-68121. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/6866abf59976d273164a6624234d96a967280223
- https://git.kernel.org/stable/c/6eed5ae7887a93160803d2b81ff88e75eefd4a4c
- https://git.kernel.org/stable/c/7a56e7c9b08e08fd55a1bcada24cf4fe3782b722
- https://git.kernel.org/stable/c/7e9fbd7f96bcde63a7c798fe16b38cedee7a1501
- https://git.kernel.org/stable/c/ba3409369c5413cdf0dcbf3a928f76b48e8c3e6a
- https://git.kernel.org/stable/c/bed4caecd723693f750e13adbb2c42ca1249a3fd
- https://git.kernel.org/stable/c/e6493a4d1ee17595766165fa446d45b7e0c318d0
- https://git.kernel.org/stable/c/e9c238f6fe42fb1b4dba3a578277de32cb487937