Search/CVE-2026-53221
● CVE — Critical

CVE-2026-53221

VendorlinuxProductlinux kernelDiscoveredJun 25, 2026UpdatedJul 2, 2026

In the Linux kernel, the following vulnerability has been resolved: ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup() In vti6_tnl_lookup(), when an exact match for a tunnel fails, the code falls back to searching for wildcard tunnels: Tunnels matching the packet's local address, with any remote address wildcard remote). Tunnels matching the packet's remote address, with any local address (wildcard local). However, vti6 stores all these different types of tunnels in the same hash table (ip6n->tnls_r_l) prone to hash collisions. The bug is that the fallback search loops in vti6_tnl_lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.

CVSS v3.1
9.8 CRITICAL
EPSS
0.58%
probability of exploitation in 30 days
CISA KEV
Not listed
no confirmed exploitation reported
News coverage
32
sources referencing this CVE
Related IOCs
0
seen in the same coverage
Intelligence Reports1
1 intelligence report available

Curated threat research and citations from CrowdStrike, Mandiant, Microsoft, and other sources — unlock with Premium.

Upgrade to Premium
EPSS Trend
Sep 25, 2026 → Oct 22, 2026
▼ 0.18pp
0.76% → 0.58% over 3 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
33 relationships
Timeline
disclosure → media coverage
Jun 25, 2026
Disclosure — published as a CVE record. · last revised by NVD Jul 2, 2026
Aug 12, 2026
ubuntu.com reports: USN-8629-1: Linux kernel vulnerabilities
Aug 13, 2026
ubuntu.com reports: USN-8637-1: Linux kernel (OEM) vulnerabilities
Aug 17, 2026
ubuntu.com reports: USN-8629-2: Linux kernel (AWS) vulnerabilities
Aug 18, 2026
ubuntu.com reports: USN-8629-3: Linux kernel (HWE) vulnerabilities
Aug 20, 2026
ubuntu.com reports: USN-8660-1: 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 25, 2026
ubuntu.com reports: USN-8819-2: Linux kernel 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-8819-3: Linux kernel vulnerabilities
Sep 29, 2026
ubuntu.com reports: USN-8818-3: Linux kernel vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8819-4: Linux kernel (FIPS) 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-8850-1: Linux kernel (BlueField) vulnerabilities
Sep 30, 2026
ubuntu.com reports: USN-8851-1: Linux kernel 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-8851-2: Linux kernel (Raspberry Pi) vulnerabilities
Oct 2, 2026
ubuntu.com reports: USN-8818-6: Linux kernel (FIPS) vulnerabilities
Oct 2, 2026
ubuntu.com reports: USN-8864-1: Linux kernel vulnerabilities
Oct 5, 2026
ubuntu.com reports: USN-8851-3: Linux kernel (Azure) 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