CVE-2026-68121

Published Aug 10, 2026

Last updated a month ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-68121, also known as "PPPoEject," is a use-after-free vulnerability found within the Linux kernel's Point-to-Point Protocol over Ethernet (PPPoE) implementation. The flaw arises in the `pppoe_sendmsg()` function, where a pointer to the PPPoE header is saved prior to invoking `dev_hard_header()`. Device header callbacks have the capability to reallocate the socket buffer (skb) head, which can invalidate any previously stored pointers. If the skb head is reallocated, the PPPoE implementation subsequently writes six bytes through the now-stale pointer into memory that has already been freed. This action can lead to kernel memory corruption. The vulnerability was discovered by researcher Asim Viladi Oglu Manizada and is one of several local privilege escalation (LPE) flaws recently identified in the Linux kernel.

Description
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.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Received

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Social media

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score

13

  1. Four Linux local-root vulns published with working PoCs. DirtyAH6 (CVE-2026-80844), TUNderflow (CVE-2026-81000), PPPoEject (CVE-2026-68121), DiagSpill (CVE-2026-74469). Write-up + exploits dropped after coordinated disclosure. https://t.co/K7AjqePWEf https://t.co/8RpBiQgxEN

    @PadhiyarRushi

    19 Sept 2026

    1059 Impressions

    0 Retweets

    18 Likes

    14 Bookmarks

    2 Replies

    0 Quotes

  2. News: Asim Manizada published local-root PoCs for four Linux kernel bugs (CVE-2026-80844, CVE-2026-81000, CVE-2026-68121, CVE-2026-74469). Hits unpatched multi-user hosts. Patch to a fixed kernel (6.12.109+ or your distro advisory). https://t.co/epX3rBZCdG

    @snakeyesV1

    19 Sept 2026

    62 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  3. Public exploits are out for four Linux kernel LPE flaws (CVE-2026-80844, CVE-2026-81000, CVE-2026-68121, CVE-2026-74469). Disabling unprivileged user namespaces limits exposure until patched. https://t.co/WjH2VyXgG9 https://t.co/QC14eBVf0C #2workly

    @2Workly

    18 Sept 2026

    2 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  4. Cuatro fallos en el núcleo de Linux permiten acceso root Se han revelado cuatro nuevas vulnerabilidades en el núcleo de Linux ( CVE-2026-80844, CVE-2026-81000, CVE-2026-68121 y CVE-2026-74469 ) https://t.co/1OcVOhRSPz

    @elhackernet

    18 Sept 2026

    5499 Impressions

    50 Retweets

    140 Likes

    29 Bookmarks

    1 Reply

    1 Quote

  5. 🚨 Linux kernel'de 4 kritik LPE açığı için public exploit yayınlandı! CVE-2026-80844, CVE-2026-81000, CVE-2026-68121 ve CVE-2026-74469 için çalışan PoC / Exploit github üzerinden yayınlandı. Açıklar; IPsec AH6, TUN/TAP, PPPoE ve SCTP bileşenlerindeki bellek g

    @ridvanyagli

    18 Sept 2026

    692 Impressions

    4 Retweets

    12 Likes

    5 Bookmarks

    0 Replies

    0 Quotes

  6. News: Four Linux kernel bugs give local root: DirtyAH6 (CVE-2026-80844), TUNderflow (CVE-2026-81000), PPPoEject (CVE-2026-68121), DiagSpill (CVE-2026-74469). Hits many kernels. Update to 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, or 7.2.4. https://t.co/d6MF0JA29w

    @snakeyesV1

    18 Sept 2026

    57 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  7. CVE-2026-68121 - Linux kernel pppoe_sendmsg() use-after-free via reallocated skb header. Potential memory corruption. CVSS N/A, unpatched. Update kernels once fixed. https://t.co/AnGZs1Kr6H #CVE #Linux #infosec #infosec #cybersecurity #CVE #Linux #infosec #infosec #devsecops

    @HugoValters

    10 Aug 2026

    105 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes