7.8

CVE-2026-68121: linux Use After Free

CVSS: 7.8v3.1HighReceived
AliasesUBUNTU-CVE-2026-68121DEBIAN-CVE-2026-68121
Published 10-08-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-68121 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · +0.16 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 191 · Related 173
MGASA-2026-0336MGASA-2026-0337OPENSUSE-SU-2026:21910-1RHSA-2026:71329RHSA-2026:71330RHSA-2026:71565

Showing 100 of 191. Use Open JSON for the complete list.

Timeline

  1. 10-08-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

+0.16 pp

From 0.14% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.30%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu169 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-38.38
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1014.14
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.187-1 | < 6.12.101-1 | < 7.1.6-1
  • linux-6.12< 6.12.101-1~deb12u1
Linux1 product
  • linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7a56e7c9b08e08fd55a1bcada24cf4fe3782b722 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6eed5ae7887a93160803d2b81ff88e75eefd4a4c | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ba3409369c5413cdf0dcbf3a928f76b48e8c3e6a | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < e6493a4d1ee17595766165fa446d45b7e0c318d0 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7e9fbd7f96bcde63a7c798fe16b38cedee7a1501 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6866abf59976d273164a6624234d96a967280223 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < bed4caecd723693f750e13adbb2c42ca1249a3fd | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < e9c238f6fe42fb1b4dba3a578277de32cb487937 | 2.6.12

3 vendors · 172 products

References

27 links
Show all 27 references