CVE-2026-63919 (GCVE-0-2026-63919)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-08-05 12:37
VLAI
Title
xfrm: input: hold netns during deferred transport reinjection
Summary
In the Linux kernel, the following vulnerability has been resolved: xfrm: input: hold netns during deferred transport reinjection Transport-mode reinjection stores a struct net pointer in skb->cb and uses it later from xfrm_trans_reinject(). That pointer must stay valid until the deferred callback runs. Take a netns reference when queueing deferred reinjection work and drop it after the callback completes. Use maybe_get_net() so the queueing path does not revive a namespace that is already being torn down. This keeps the existing workqueue design and fixes the netns lifetime handling in one place for all users of xfrm_trans_queue_net().
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 7ee59eda8820b758ed29e1cd3222359c7b97302c (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 2df7059a18afb7d3aee6c36cad5d371c198111d4 (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 8dfabcba6a943a7a02ebe1e1637c361ba96acbaa (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 48ce101cd630d6745b6923b5bad8358bc4c119da (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 55ddfc41451f01c588089cd74957a05311b6f202 (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 9f7ebb45a83afc3216e855e57d51bb4bc9b5232e (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < 9f67a36e91bb50d358760f381f233913fe5c09f8 (git)
Affected: 7b3801927e52f8621de311277f7fc727635019e7 , < c16f74dc1d75d0e2e7670076d5375deda110ebeb (git)
Create a notification for this product.
Linux Linux Affected: 5.6
Unaffected: 0 , < 5.6 (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: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_input.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "7ee59eda8820b758ed29e1cd3222359c7b97302c",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "2df7059a18afb7d3aee6c36cad5d371c198111d4",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "8dfabcba6a943a7a02ebe1e1637c361ba96acbaa",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "48ce101cd630d6745b6923b5bad8358bc4c119da",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "55ddfc41451f01c588089cd74957a05311b6f202",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "9f7ebb45a83afc3216e855e57d51bb4bc9b5232e",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "9f67a36e91bb50d358760f381f233913fe5c09f8",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            },
            {
              "lessThan": "c16f74dc1d75d0e2e7670076d5375deda110ebeb",
              "status": "affected",
              "version": "7b3801927e52f8621de311277f7fc727635019e7",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_input.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.6"
            },
            {
              "lessThan": "5.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "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": "5.10.259",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.210",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.176",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.143",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.93",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.35",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.12",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: input: hold netns during deferred transport reinjection\n\nTransport-mode reinjection stores a struct net pointer in skb-\u003ecb and\nuses it later from xfrm_trans_reinject(). That pointer must stay valid\nuntil the deferred callback runs.\n\nTake a netns reference when queueing deferred reinjection work and drop\nit after the callback completes. Use maybe_get_net() so the queueing\npath does not revive a namespace that is already being torn down.\n\nThis keeps the existing workqueue design and fixes the netns lifetime\nhandling in one place for all users of xfrm_trans_queue_net()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable path is reached when IPsec ESP/AH packets are received and processed through xfrm_input transport-mode reinjection, which is a network packet receive path in net/xfrm. Remote peers can send ESP traffic to trigger deferred queueing on systems with IPsec configured.\nAC:L - The attacker controls both sides of the race by flooding IPsec packets to queue deferred reinjection work while concurrently destroying the network namespace, making the UAF reliably triggerable without conditions outside attacker control.\nPR:L - Exploitation requires configuring xfrm/IPsec and managing network namespace lifecycle, both reachable with CAP_NET_ADMIN obtainable by an unprivileged user via user namespaces (unshare -Urn), not requiring real root in the init namespace.\nUI:N - No victim user interaction is required; exploitation is achieved through automated packet transmission and namespace teardown scripted by the attacker.\nS:U - Impact is kernel memory corruption and potential privilege escalation within the same security authority; this is not a VM escape or cross-authority boundary bypass.\nC:H - The deferred callback dereferences a freed struct net (e.g., ip6_rcv_finish_core reads sysctl fields from the UAF pointer), providing an information disclosure primitive from attacker-influenced freed slab memory.\nI:H - Use-after-free on the large struct net slab object enables heap grooming and memory corruption exploitable for arbitrary kernel writes and control-flow hijacking, not merely a bounded modification.\nA:H - Dereferencing a freed network namespace structure causes kernel oops/panic from the workqueue callback path, and UAF reliably threatens system availability even when full exploitation is not attempted."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:37:13.727Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/7ee59eda8820b758ed29e1cd3222359c7b97302c"
        },
        {
          "url": "https://git.kernel.org/stable/c/2df7059a18afb7d3aee6c36cad5d371c198111d4"
        },
        {
          "url": "https://git.kernel.org/stable/c/8dfabcba6a943a7a02ebe1e1637c361ba96acbaa"
        },
        {
          "url": "https://git.kernel.org/stable/c/48ce101cd630d6745b6923b5bad8358bc4c119da"
        },
        {
          "url": "https://git.kernel.org/stable/c/55ddfc41451f01c588089cd74957a05311b6f202"
        },
        {
          "url": "https://git.kernel.org/stable/c/9f7ebb45a83afc3216e855e57d51bb4bc9b5232e"
        },
        {
          "url": "https://git.kernel.org/stable/c/9f67a36e91bb50d358760f381f233913fe5c09f8"
        },
        {
          "url": "https://git.kernel.org/stable/c/c16f74dc1d75d0e2e7670076d5375deda110ebeb"
        }
      ],
      "title": "xfrm: input: hold netns during deferred transport reinjection",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63919",
    "datePublished": "2026-07-19T14:55:22.121Z",
    "dateReserved": "2026-07-19T07:54:57.020Z",
    "dateUpdated": "2026-08-05T12:37:13.727Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-63919",
      "date": "2026-08-11",
      "epss": "0.00633",
      "percentile": "0.47077"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-63919\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T16:17:10.030\",\"lastModified\":\"2026-07-27T17:44:23.777\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nxfrm: input: hold netns during deferred transport reinjection\\n\\nTransport-mode reinjection stores a struct net pointer in skb-\u003ecb and\\nuses it later from xfrm_trans_reinject(). That pointer must stay valid\\nuntil the deferred callback runs.\\n\\nTake a netns reference when queueing deferred reinjection work and drop\\nit after the callback completes. Use maybe_get_net() so the queueing\\npath does not revive a namespace that is already being torn down.\\n\\nThis keeps the existing workqueue design and fixes the netns lifetime\\nhandling in one place for all users of xfrm_trans_queue_net().\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/xfrm/xfrm_input.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"7ee59eda8820b758ed29e1cd3222359c7b97302c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"2df7059a18afb7d3aee6c36cad5d371c198111d4\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"8dfabcba6a943a7a02ebe1e1637c361ba96acbaa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"48ce101cd630d6745b6923b5bad8358bc4c119da\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"55ddfc41451f01c588089cd74957a05311b6f202\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"9f7ebb45a83afc3216e855e57d51bb4bc9b5232e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"9f67a36e91bb50d358760f381f233913fe5c09f8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b3801927e52f8621de311277f7fc727635019e7\",\"lessThan\":\"c16f74dc1d75d0e2e7670076d5375deda110ebeb\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/xfrm/xfrm_input.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.6\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.6\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.259\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.210\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.176\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.143\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.93\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.35\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.12\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2df7059a18afb7d3aee6c36cad5d371c198111d4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/48ce101cd630d6745b6923b5bad8358bc4c119da\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/55ddfc41451f01c588089cd74957a05311b6f202\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7ee59eda8820b758ed29e1cd3222359c7b97302c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8dfabcba6a943a7a02ebe1e1637c361ba96acbaa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9f67a36e91bb50d358760f381f233913fe5c09f8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9f7ebb45a83afc3216e855e57d51bb4bc9b5232e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c16f74dc1d75d0e2e7670076d5375deda110ebeb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-05T14:20:26+00:00",
      "cve": "CVE-2026-63919",
      "id": "CVE-2026-63919",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "246",
      "product_status:known_not_affected": "28",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: xfrm: input: hold netns during deferred transport reinjection",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63919.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-08-10T16:25:26Z",
      "cve": "CVE-2026-63919",
      "id": "CVE-2026-63919",
      "initial_release_date": "2026-07-21T13:03:34Z",
      "product_status:first_fixed": "272",
      "product_status:known_affected": "73",
      "product_status:known_not_affected": "213",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-63919",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-63919.json",
      "version": "6"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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

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.