CVE-2026-43493 (GCVE-0-2026-43493)
Vulnerability from cvelistv5
Published
2026-05-19 10:44
Modified
2026-08-05 12:28
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: crypto: pcrypt - Fix handling of MAY_BACKLOG requests MAY_BACKLOG requests can return EBUSY. Handle them by checking for that value and filtering out EINPROGRESS notifications.
References
Impacted products
Vendor Product Version
Linux Linux Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
Version: 5a1436beec5744029f3ac90b6fe71a698dcd6155
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "crypto/pcrypt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ae7e95638d956d556d74b9abb9e780d3bd3dcd9e",
              "status": "affected",
              "version": "5a1436beec5744029f3ac90b6fe71a698dcd6155",
              "versionType": "git"
            },
            {
              "lessThan": "1d7f07df450bac3301938fbc4251f2611be4084e",
              "status": "affected",
              "version": "5a1436beec5744029f3ac90b6fe71a698dcd6155",
              "versionType": "git"
            },
            {
              "lessThan": "76641449b28979ebd6c02e9598367e119e385236",
              "status": "affected",
              "version": "5a1436beec5744029f3ac90b6fe71a698dcd6155",
              "versionType": "git"
            },
            {
              "lessThan": "9f1cbca178c03188e201ed175251372149bb25f2",
              "status": "affected",
              "version": "5a1436beec5744029f3ac90b6fe71a698dcd6155",
              "versionType": "git"
            },
            {
              "lessThan": "eb34e243df57e32f4c08fa191f3602ea19076276",
              "status": "affected",
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              "versionType": "git"
            },
            {
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            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "5a1436beec5744029f3ac90b6fe71a698dcd6155",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "crypto/pcrypt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.34"
            },
            {
              "lessThan": "2.6.34",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.258",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.140",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.86",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.27",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.258",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.209",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.175",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.140",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.86",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.27",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.4",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: pcrypt - Fix handling of MAY_BACKLOG requests\n\nMAY_BACKLOG requests can return EBUSY.  Handle them by checking\nfor that value and filtering out EINPROGRESS notifications."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - pcrypt AEAD can sit under network-facing kernel crypto consumers such as kTLS/TIPC that process peer-supplied records or packets. In the highest reasonable deployment, a remote peer can drive the vulnerable encrypt/decrypt path through network traffic.\nAC:L - The trigger is child crypto backlog behavior under `CRYPTO_TFM_REQ_MAY_BACKLOG`; an attacker can induce queue pressure with concurrent requests or traffic. There is no race that depends on conditions outside the attacker\u0027s control.\nPR:N - The network-facing path requires no kernel privileges from the remote peer. The local AF_ALG AEAD path also has no capability gate, but the higher-severity network scenario is defensible.\nUI:N - No victim interaction is required once the affected crypto consumer is configured. The attacker only sends data or submits crypto requests.\nS:U - The bug corrupts kernel crypto/request state within the same kernel security authority. It is not a VM escape, IOMMU bypass, or other scope-changing boundary crossing.\nC:H - Mishandling `-EBUSY` can complete and free the request while the child request remains queued, leading to use-after-free on later callbacks. A kernel UAF is reasonably exploitable for high-impact information disclosure.\nI:H - The stale callback reuses freed request/padata memory and can drive list operations and completion paths on attacker-reclaimed objects. This is memory corruption with a plausible path to arbitrary write or control-flow corruption.\nA:H - At minimum, the premature completion and later queued callback can dereference or manipulate freed kernel memory. That can produce kernel oops/panic or list corruption, giving high availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:28:16.602Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ae7e95638d956d556d74b9abb9e780d3bd3dcd9e"
        },
        {
          "url": "https://git.kernel.org/stable/c/1d7f07df450bac3301938fbc4251f2611be4084e"
        },
        {
          "url": "https://git.kernel.org/stable/c/76641449b28979ebd6c02e9598367e119e385236"
        },
        {
          "url": "https://git.kernel.org/stable/c/9f1cbca178c03188e201ed175251372149bb25f2"
        },
        {
          "url": "https://git.kernel.org/stable/c/eb34e243df57e32f4c08fa191f3602ea19076276"
        },
        {
          "url": "https://git.kernel.org/stable/c/77d55bc8675ee851ed639dc9be77325a8024cf67"
        },
        {
          "url": "https://git.kernel.org/stable/c/46271895ddfb1ba41f89f7e0dffbe9c2bcf7380a"
        },
        {
          "url": "https://git.kernel.org/stable/c/915b692e6cb723aac658c25eb82c58fd81235110"
        }
      ],
      "title": "crypto: pcrypt - Fix handling of MAY_BACKLOG requests",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43493",
    "datePublished": "2026-05-19T10:44:25.402Z",
    "dateReserved": "2026-05-01T14:12:56.013Z",
    "dateUpdated": "2026-08-05T12:28:16.602Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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