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CVE-2026-89751 (GCVE-0-2026-89751)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-09-14 12:02
VLAI
Title
x86/tdx: Fix off-by-one in port I/O handling
Summary
In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use: u64 mask = GENMASK(BITS_PER_BYTE * size, 0); GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes. Fix the mask calculation.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < c6875423ad849ac234ab9812eb72f37ff8a490b4 (git)
Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < 220011fe95fc78b2bc2d7d43893bc73957a5c811 (git)
Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < 222b7005e4519f633b4cd666226256abbab46a1a (git)
Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < c4a22154870813d10aa0b4c734a574c726f9d4b0 (git)
Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < bb45f705c4440dd3c689328319b88dd28770bbb8 (git)
Affected: 03149948832a078f759022ed5b92e722d8d23c26 , < 0f63e656b1c679d32ac595de29d10c03efca6a25 (git)
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Linux Linux Affected: 5.19
Unaffected: 0 , < 5.19 (semver)
Unaffected: 6.1.188 , ≤ 6.1.* (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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      "cve": "CVE-2026-89751",
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      "cve": "CVE-2026-89751",
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      "initial_release_date": "2026-09-12T16:22:13Z",
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • 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.


Detection rules are retrieved from Rulezet.


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.