Vulnerability-Lookup

FKIE_CVE-2026-53402

Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-08-17 05:17

Severity

7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font() When fbcon_do_set_font() fails (e.g., due to a memory allocation failure inside vc_resize() under heavy memory pressure), it jumps to the `err_out` label to roll back the console state. However, the current rollback logic forgets to restore the `hi_font` state, leading to a severe state machine corruption. Earlier in the function, `set_vc_hi_font()` might be called to change `vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()` subsequently fails, the `err_out` path restores `vc_font.charcount` but entirely skips rolling back the `vc_hi_font_mask` and the screen buffer. This mismatch leaves the terminal in a desynchronized state. Because `vc_hi_font_mask` remains set, the VT subsystem will still accept character indices greater than 255 from userspace and write them to the screen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will then use these inflated indices to access the reverted, 256-character font array, leading to a deterministic out-of-bounds read and potential kernel memory disclosure. Fix this by adding the missing rollback logic for the `hi_font` mask and screen buffer in the error path.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bc	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	6.0
linux	linux_kernel	6.0
linux	linux_kernel	6.0
linux	linux_kernel	6.0
linux	linux_kernel	6.0
linux	linux_kernel	6.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbcon.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cb016bcb40c81e7b19c4ae6143babb366dae8e20",
              "status": "affected",
              "version": "868749a7456dc48e93887a8474194e2ee6d6c21f",
              "versionType": "git"
            },
            {
              "lessThan": "ac562193c36696513ae196171892e9338475c4bc",
              "status": "affected",
              "version": "ebd6f886aa2447fcfcdce5450c9e1028e1d681bb",
              "versionType": "git"
            },
            {
              "lessThan": "3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "a7a526fbc847f07ad3a503c7382189be5ab68574",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "b5bb2c696e140c399cb874def2feedf61dee27d6",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "076b1aa65f77a49bce5a48a4a55a397cfcafa2b8",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "39815715cbcfabb16fc8c5f4a23deeda20f5df62",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f08ccb792d3eaf1dc62d8cbf6a30d6522329f660",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.261",
              "status": "affected",
              "version": "5.10.249",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.212",
              "status": "affected",
              "version": "5.15.64",
              "versionType": "semver"
            },
            {
              "lessThan": "5.20",
              "status": "affected",
              "version": "5.19.6",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbcon.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B7E36D96-72CA-4974-A809-29C9A2541071",
              "versionEndExcluding": "5.10.261",
              "versionStartIncluding": "5.10.249",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0D866C5E-CE49-4FE6-9E1A-F7E438921074",
              "versionEndExcluding": "5.15.212",
              "versionStartIncluding": "5.15.64",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6E53B030-2C91-45B9-91A0-63E897460E68",
              "versionEndExcluding": "6.0",
              "versionStartIncluding": "5.19.6",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "22C9EAD8-0845-4C82-A958-43F2EDB3B88D",
              "versionEndExcluding": "6.1.178",
              "versionStartIncluding": "6.0.1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7046B092-F810-4440-ACE6-60218518EECE",
              "versionEndExcluding": "6.6.145",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "38A8100E-2B1A-462F-AEE9-8901B870FEF2",
              "versionEndExcluding": "6.12.96",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7",
              "versionEndExcluding": "6.18.39",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "9526B150-E2B3-4C6F-8AE5-1AF92B75AD9E",
              "versionEndExcluding": "7.1.3",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:-:*:*:*:*:*:*",
              "matchCriteriaId": "7BE551E5-89CF-47A8-9B26-03CE727FBA37",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "A46498B3-78E1-4623-AAE1-94D29A42BE4E",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "F8446E87-F5F6-41CA-8201-BAE0F0CA6DD9",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "8E5FB72F-67CE-43CC-83FE-541604D98182",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc6:*:*:*:*:*:*",
              "matchCriteriaId": "3A0A7397-F5F8-4753-82DC-9A11288E696D",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc7:*:*:*:*:*:*",
              "matchCriteriaId": "E6DE049A-ABA8-41DD-988C-8C088358EE9B",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()\n\nWhen fbcon_do_set_font() fails (e.g., due to a memory allocation failure\ninside vc_resize() under heavy memory pressure), it jumps to the `err_out`\nlabel to roll back the console state. However, the current rollback logic\nforgets to restore the `hi_font` state, leading to a severe state machine\ncorruption.\n\nEarlier in the function, `set_vc_hi_font()` might be called to change\n`vc-\u003evc_hi_font_mask` and mutate the screen buffer. If `vc_resize()`\nsubsequently fails, the `err_out` path restores `vc_font.charcount`\nbut entirely skips rolling back the `vc_hi_font_mask` and the screen\nbuffer.\n\nThis mismatch leaves the terminal in a desynchronized state. Because\n`vc_hi_font_mask` remains set, the VT subsystem will still accept\ncharacter indices greater than 255 from userspace and write them to the\nscreen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will\nthen use these inflated indices to access the reverted, 256-character\nfont array, leading to a deterministic out-of-bounds read and potential\nkernel memory disclosure.\n\nFix this by adding the missing rollback logic for the `hi_font` mask\nand screen buffer in the error path."
    }
  ],
  "id": "CVE-2026-53402",
  "lastModified": "2026-08-17T05:17:15.080",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T12:16:51.387",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-53402 (GCVE-0-2026-53402)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:02 – Updated: 2026-08-17 04:50

Title

fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()

Summary

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/cb016bcb40c81e7b1…
https://git.kernel.org/stable/c/ac562193c36696513…
https://git.kernel.org/stable/c/3618a4c5b2591cfa8…
https://git.kernel.org/stable/c/a7a526fbc847f07ad…
https://git.kernel.org/stable/c/b5bb2c696e140c399…
https://git.kernel.org/stable/c/076b1aa65f77a49bc…
https://git.kernel.org/stable/c/39815715cbcfabb16…
https://git.kernel.org/stable/c/8fdc8c2057eea08d4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 868749a7456dc48e93887a8474194e2ee6d6c21f , < cb016bcb40c81e7b19c4ae6143babb366dae8e20 (git) Affected: ebd6f886aa2447fcfcdce5450c9e1028e1d681bb , < ac562193c36696513ae196171892e9338475c4bc (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < a7a526fbc847f07ad3a503c7382189be5ab68574 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < b5bb2c696e140c399cb874def2feedf61dee27d6 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 076b1aa65f77a49bce5a48a4a55a397cfcafa2b8 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 39815715cbcfabb16fc8c5f4a23deeda20f5df62 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2 (git) Affected: f08ccb792d3eaf1dc62d8cbf6a30d6522329f660 (git) Affected: 5.10.249 , < 5.10.261 (semver) Affected: 5.15.64 , < 5.15.212 (semver) Affected: 5.19.6 , < 5.20 (semver)
Linux	Linux	Affected: 6.0 Unaffected: 0 , < 6.0 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.3 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbcon.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cb016bcb40c81e7b19c4ae6143babb366dae8e20",
              "status": "affected",
              "version": "868749a7456dc48e93887a8474194e2ee6d6c21f",
              "versionType": "git"
            },
            {
              "lessThan": "ac562193c36696513ae196171892e9338475c4bc",
              "status": "affected",
              "version": "ebd6f886aa2447fcfcdce5450c9e1028e1d681bb",
              "versionType": "git"
            },
            {
              "lessThan": "3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "a7a526fbc847f07ad3a503c7382189be5ab68574",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "b5bb2c696e140c399cb874def2feedf61dee27d6",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "076b1aa65f77a49bce5a48a4a55a397cfcafa2b8",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "39815715cbcfabb16fc8c5f4a23deeda20f5df62",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "lessThan": "8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2",
              "status": "affected",
              "version": "a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f08ccb792d3eaf1dc62d8cbf6a30d6522329f660",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.261",
              "status": "affected",
              "version": "5.10.249",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.212",
              "status": "affected",
              "version": "5.15.64",
              "versionType": "semver"
            },
            {
              "lessThan": "5.20",
              "status": "affected",
              "version": "5.19.6",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbcon.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.261",
                  "versionStartIncluding": "5.10.249",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.212",
                  "versionStartIncluding": "5.15.64",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.96",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.3",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.19.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()\n\nWhen fbcon_do_set_font() fails (e.g., due to a memory allocation failure\ninside vc_resize() under heavy memory pressure), it jumps to the `err_out`\nlabel to roll back the console state. However, the current rollback logic\nforgets to restore the `hi_font` state, leading to a severe state machine\ncorruption.\n\nEarlier in the function, `set_vc_hi_font()` might be called to change\n`vc-\u003evc_hi_font_mask` and mutate the screen buffer. If `vc_resize()`\nsubsequently fails, the `err_out` path restores `vc_font.charcount`\nbut entirely skips rolling back the `vc_hi_font_mask` and the screen\nbuffer.\n\nThis mismatch leaves the terminal in a desynchronized state. Because\n`vc_hi_font_mask` remains set, the VT subsystem will still accept\ncharacter indices greater than 255 from userspace and write them to the\nscreen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will\nthen use these inflated indices to access the reverted, 256-character\nfont array, leading to a deterministic out-of-bounds read and potential\nkernel memory disclosure.\n\nFix this by adding the missing rollback logic for the `hi_font` mask\nand screen buffer in the error path."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerability is reached only through the KDFONTOP ioctl on a framebuffer-console virtual terminal (/dev/ttyN), which is a local syscall path with no network or physical-access vector.\nAC:L - An attacker who controls a session on an fbcon-backed VT can reliably trigger the bug by issuing a font-change ioctl with different dimensions and a 256\u2194512 glyph transition, then inducing vc_resize() failure through self-controlled memory pressure; no race or victim-dependent timing is required.\nPR:L - KDFONTOP font-set operations require only that the caller owns the controlling TTY (current-\u003esignal-\u003etty == tty), which any unprivileged local user with a console or VT session has; CAP_SYS_TTY_CONFIG is not required on that path.\nUI:N - Exploitation requires only the attacker\u0027s own ioctl and memory-pressure actions on their TTY; no action by another user or administrator is needed.\nS:U - Impact is confined to kernel memory disclosure and potential kernel crash within the same kernel security authority; there is no VM escape, sandbox escape, or cross-security-boundary effect.\nC:H - The desynchronized hi_font_mask causes deterministic out-of-bounds reads from the kernel font glyph buffer during fbcon rendering (e.g., bit_cursor and rotated putcs paths), enabling disclosure of adjacent kernel memory.\nI:N - The flaw is an out-of-bounds read with console state desynchronization; it does not provide an arbitrary kernel write, code execution, or other data-modification primitive.\nA:H - Out-of-bounds reads from kernel font data can cause kernel page faults and oopses, consistent with the prior syzkaller-reported fbcon font/resize failure class that produced unhandled page faults."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:50:55.659Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bc"
        },
        {
          "url": "https://git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5"
        },
        {
          "url": "https://git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574"
        },
        {
          "url": "https://git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6"
        },
        {
          "url": "https://git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8"
        },
        {
          "url": "https://git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62"
        },
        {
          "url": "https://git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2"
        }
      ],
      "title": "fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53402",
    "datePublished": "2026-07-19T12:02:01.795Z",
    "dateReserved": "2026-06-09T07:44:35.403Z",
    "dateUpdated": "2026-08-17T04:50:55.659Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

FKIE_CVE-2026-53402

CVE-2026-53402 (GCVE-0-2026-53402)

Tags

Sightings

Nomenclature