GHSA-5xjr-h8mp-chfc · Severity: high — In the Linux kernel, the following vulnerability has been resolved: l2tp: pppol2tp: hold...
In the Linux kernel, the following vulnerability has been resolved: l2tp: pppol2tp: hold reference to session in pppol2tp_ioctl() pppol2tp_ioctl() read sock->sk->sk_user_data directly without any locks or reference counting. If a controllable sleep was induced during copy_from_user() (e.g. via a userfaultfd page fault sleep), a concurrent socket close could trigger pppol2tp_session_close() asynchronously. This frees the l2tp_session structure via the l2tp_session_del_work workqueue. Upon resuming, the ioctl thread dereferences the stale session pointer, resulting in a Use-After-Free (UAF). Fix this by securely fetching the session reference using the RCU-safe, refcounted helper pppol2tp_sock_to_session(sk) on entry. This locks the session's refcount across the sleep. We structured the function to exit via standard err breaks, guaranteeing that l2tp_session_put() is cleanly called on all return paths to drop the reference. To preserve existing behavior we validate the session and its magic signature only for the specific L2TP commands that require it. This ensures that generic/unknown ioctls called on an unconnected socket still return -ENOIOCTLCMD and correctly fall back to generic handlers (e.g. in sock_do_ioctl()).
Conclusion & alert: CVE-2026-53262 is rated Low Risk (32.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.12%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-28 | 0.16% | 0.12% | -0.04% |
| 2 | 2026-06-25 | — | 0.16% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
GHSA-5xjr-h8mp-chfc · Severity: high — In the Linux kernel, the following vulnerability has been resolved: l2tp: pppol2tp: hold...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-53262 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. | https://security-tracker.debian.org/tracker/CVE-2026-53262 |
redhat
|
— | — | https://access.redhat.com/security/cve/CVE-2026-53262 |
suse
|
high | — | https://www.suse.com/security/cve/CVE-2026-53262/ |
ubuntu
|
high | CVE-2026-53262 high priority: Ubuntu including 162 source packages (linux, linux-allwinner-5.19, …), 1458 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1051, ignored 172, needed 147, released 88. | https://ubuntu.com/security/CVE-2026-53262 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | >= 2.6.35, < 6.12.94 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.13, < 6.18.36 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.19, < 7.0.13 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* |
| linux | linux_kernel | 7.1 | cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* |