CVE-2026-53221
ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
Description
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.
INFO
Published Date :
June 25, 2026, 9:16 a.m.
Last Modified :
July 2, 2026, 8:49 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel.
- Verify tunnel lookup logic.
- Apply relevant security patches.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53221.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53221 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53221
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53221 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53221 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Jul. 02, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.143 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 3.19 up to (excluding) 5.10.259 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* Added Reference Type kernel.org: https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': 'c327fa4fca31415431202e063767a7ae342e19c6', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': 'fc657ac0767c49839b3ef0b08dc0953ca30883f8', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': '47fb3c2b4203556308e64354b3e78f2ce221d646', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': 'f513f308cc4bdb4530d033431592ffbc29b7fca1', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': '90fd4513315ca07da99cfd8549d3e553a7160f0d', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': '2abfb19bbb81958714ad1d43ebeb65b30394184b', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': '2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d', 'versionType': 'git'}, {'status': 'affected', 'version': 'fbe68ee87522f6eaa10f9076c0a7117e1613f2f7', 'lessThan': 'a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9', 'versionType': 'git'}], 'programFiles': ['net/ipv6/ip6_vti.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.94', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.36', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.13', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv6/ip6_vti.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/2abfb19bbb81958714ad1d43ebeb65b30394184b Added Reference https://git.kernel.org/stable/c/2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d Added Reference https://git.kernel.org/stable/c/47fb3c2b4203556308e64354b3e78f2ce221d646 Added Reference https://git.kernel.org/stable/c/90fd4513315ca07da99cfd8549d3e553a7160f0d Added Reference https://git.kernel.org/stable/c/a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9 Added Reference https://git.kernel.org/stable/c/c327fa4fca31415431202e063767a7ae342e19c6 Added Reference https://git.kernel.org/stable/c/f513f308cc4bdb4530d033431592ffbc29b7fca1 Added Reference https://git.kernel.org/stable/c/fc657ac0767c49839b3ef0b08dc0953ca30883f8