8.4

CVE-2026-63828: linux

CVSS: 8.4v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-63828DEBIAN-CVE-2026-63828
Published 19-07-2026Last modified 17-08-2026
Open JSON

Vulnerability summary

CVE-2026-63828 is a high (CVSS 8.4) vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.9% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.4/10
010
High · v3.1 (CVE.org)
EPSS score
0.17%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 33 · Related 32
MGASA-2026-0312OPENSUSE-SU-2026:11339-1OPENSUSE-SU-2026:21910-1SUSE-SU-2026:23477-1SUSE-SU-2026:23481-1SUSE-SU-2026:23528-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: mediate the implicit connect of TCP fast open sendmsg sendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and write(2): it opens the connection in the SYN. apparmor_socket_sendmsg() only checks AA_MAY_SEND, so a profile that grants send but denies connect lets a confined task open an outbound TCP/MPTCP connection that connect(2) would have refused, bypassing connect mediation. Mediate the implicit connect when MSG_FASTOPEN is set and a destination is supplied. Add it to apparmor_socket_sendmsg() (not the shared aa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm() directly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not cover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

0.00 pp

From 0.17% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.17%

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

No weakness data has been published for this record.

Affected systems

Ubuntu169 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.177-1 | < 6.12.95-1 | < 7.1.3-1
Linux1 product
  • linux≥ cf60af03ca4e71134206809ea892e49b92a88896, < a16714e7cf2baa98ba2efddd5d6cbac641f4e76b | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 20383429b56974507c465d016e5238b189f7a246 | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 7f57428ce00891d26b0f087ef754a4d820ec83aa | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < faea60deaa05c76f0772650f42eafde12bd39d93 | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 07b71c342382b854ab8030b244aeab6a7228ad7d | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 4a69b83045d3195d5b9a9b053ad840ddb2998b4e | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 45ebb934ea50b436ce49b2f159f090dab0d7fa28 | ≥ cf60af03ca4e71134206809ea892e49b92a88896, < 4d587cd8a72155089a627130bbd4716ec0856e21 | 3.6

3 vendors · 171 products

References

33 links
Show all 33 references