Search/CVE-2026-63993
● CVE — Critical

CVE-2026-63993

VendorlinuxProductlinux kernelDiscoveredJul 19, 2026UpdatedOct 2, 2026

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.

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CVSS v3.1
9.8 CRITICAL
EPSS
0.51%
probability of exploitation in 30 days
CISA KEV
Not listed
no confirmed exploitation reported
News coverage
22
sources referencing this CVE
Related IOCs
0
seen in the same coverage
EPSS Trend
Aug 26, 2026 → Sep 27, 2026
▼ 0.24pp
0.76% → 0.51% over 4 tracked changes
CVSS v3.1 Detail
Attack VectorNETWORK
Attack ComplexityLOW
Privileges RequiredNONE
User InteractionNONE
ScopeUNCHANGED
ConfidentialityHIGH
IntegrityHIGH
AvailabilityHIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Connections
24 relationships
Timeline
disclosure → media coverage
Jul 19, 2026
Disclosure — published as a CVE record. · last revised by NVD Oct 2, 2026
Jul 23, 2026
ubuntu.com reports: USN-8593-1: Linux kernel vulnerabilities
Jul 24, 2026
ubuntu.com reports: USN-8603-1: Linux kernel (Azure) vulnerabilities
Jul 28, 2026
ubuntu.com reports: USN-8618-1: Linux kernel vulnerabilities
Aug 20, 2026
ubuntu.com reports: USN-8663-1: Linux kernel (NVIDIA) vulnerabilities
Aug 20, 2026
ubuntu.com reports: USN-8664-1: Linux kernel (NVIDIA BaseOS) vulnerabilities
Sep 7, 2026
ubuntu.com reports: USN-8728-1: Linux kernel (GCP) vulnerabilities
Sep 18, 2026
ubuntu.com reports: USN-8781-1: Linux kernel (NVIDIA Tegra) vulnerabilities
Sep 22, 2026
ubuntu.com reports: USN-8728-2: Linux kernel (Azure) vulnerabilities
Sep 24, 2026
ubuntu.com reports: USN-8817-1: Linux kernel vulnerabilities
Sep 24, 2026
ubuntu.com reports: USN-8818-1: Linux kernel vulnerabilities
Sep 25, 2026
ubuntu.com reports: USN-8818-2: Linux kernel (IBM) vulnerabilities
Sep 29, 2026
ubuntu.com reports: USN-8728-3: Linux kernel (Oracle) vulnerabilities
Sep 29, 2026
ubuntu.com reports: USN-8842-1: Linux kernel (NVIDIA) vulnerabilities
Sep 29, 2026
ubuntu.com reports: USN-8818-3: Linux kernel vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8818-4: Linux kernel vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8849-1: Linux kernel (NVIDIA Tegra) vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8818-5: Linux kernel (NVIDIA Tegra) vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8817-3: Linux kernel (AWS) vulnerabilities
Oct 2, 2026
ubuntu.com reports: USN-8818-6: Linux kernel (FIPS) vulnerabilities
Oct 5, 2026
ubuntu.com reports: USN-8871-1: Linux kernel (Raspberry Pi) vulnerabilities
Oct 6, 2026
ubuntu.com reports: USN-8878-1: Linux kernel (GCP) vulnerabilities
Oct 6, 2026
ubuntu.com reports: USN-8879-1: Linux kernel (Oracle) vulnerabilities