Highly exploitable, CVE-2026-68121 poses a critical security risk that could lead to severe breaches.
Status: Received on 10 Aug 2026, 13:19 UTC
Last updated: 🕔 19 Aug 2026, 17:20 UTC
Originally published on: 🕐 10 Aug 2026, 13:19 UTC
Time between publication and last update: 9 days
CVSS Release: version 3
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVE-2026-68121: 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.
The exploitability of CVE-2026-68121 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2026-68121 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-68121, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-68121, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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