CVE-2026-53221 (GCVE-0-2026-53221)

Vulnerability from cvelistv5 – Published: 2026-06-25 08:39 – Updated: 2026-10-19 19:57
VLAI
Title
ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
Summary
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.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 15:27 UTC
CWE
  • CWE-20 - Improper Input Validation
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6641 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < c327fa4fca31415431202e063767a7ae342e19c6 (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < fc657ac0767c49839b3ef0b08dc0953ca30883f8 (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < 47fb3c2b4203556308e64354b3e78f2ce221d646 (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < f513f308cc4bdb4530d033431592ffbc29b7fca1 (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < 90fd4513315ca07da99cfd8549d3e553a7160f0d (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < 2abfb19bbb81958714ad1d43ebeb65b30394184b (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < 2fc7bc087cc7085368263d9d37bfe9a0bddd6a2d (git)
Affected: fbe68ee87522f6eaa10f9076c0a7117e1613f2f7 , < a5c0359f5cbc51a2e2b114d6041e0f3c73f903e9 (git)
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Linux Linux Affected: 3.19
Unaffected: 0 , < 3.19 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.94 , ≤ 6.12.* (semver)
Unaffected: 6.18.36 , ≤ 6.18.* (semver)
Unaffected: 7.0.13 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Affected: 0 , < * (custom)
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Show details on NVD website
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Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

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    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.