Status: UPDATED | Advisory ID: CVE-2026-63993
| CVE | CVE-2026-63993 |
| CVSS Score / Version | 9.8 (Critical) / CVSS v3.1 |
| Updated | 2026-10-02 |
| CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | Linux Linux Kernel and Linux Linux |
| Classified as | CWE-416 (Use After Free) |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Linux | Linux Kernel | ||
| Linux | Linux |
| Subsystems | General OT |
| Sectors | All Sectors |
In the Linux kernel, the following vulnerability has been resolved:
vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
skb_tunnel_check_pmtu() can change skb->head.
Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF.
Use instead ip_hdr(skb) as done in drivers/net/bareudp.c
and drivers/net/geneve.c.
Found by Sashiko. (NVD)
Monitor Linux's web page for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-63993 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-63993 |