CVE-2026-68398
CVE-2026-68398: 1 tracked advisory record across Red Hat. Compare vendor sources and published fix guidance.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityHigh7.8
High [CVE-2026-68398] Linux kernel: PPP over L2TP Use-After-Free vulnerability
CVE-2026-68398Source published Source updated
In the Linux kernel, the following vulnerability has been resolved: ppp: defer channel free to an RCU grace period to fix pppol2tp RX UAF pppol2tp_recv() runs in the L2TP UDP-encap softirq RX path: l2tp_udp_encap_recv() -> l2tp_recv_common() -> pppol2tp_recv() -> ppp_input(&po->chan) It runs under rcu_read_lock() holding only an l2tp_session reference and takes NO reference on the internal PPP channel (struct channel, chan->ppp) that ppp_input() dereferences. The pppox socket is SOCK_RCU_FREE, so 'po' and the embedded ppp_channel are RCU-safe. But the internal struct channel is a separate allocation that ppp_release_channel() frees with a plain kfree(): close(data socket) -> pppol2tp_release() -> pppox_unbind_sock() -> ppp_unregister_channel() -> ppp_release_channel() -> kfree(pch) For a…
- Affected products in this advisory
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat package: kernel-rt
- Source-reported affected versions
- Affected-version details not available in this record.
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- If PPP over L2TP functionality is not required, prevent the 'pppol2tp' kernel module from loading to mitigate this vulnerability. Create a file named `/etc/modprobe.d/disable-pppol2tp.conf` with the following content: ``` install pppol2tp /bin/true ``` After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. This action may impact services relying on PPP over L2TP.
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