CVE-2026-68426

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix stale skb->prev after async crypto steals a GSO segment skb_gso_segment() leaves the segment list head with ->prev pointing at the last segment, an invariant validate_xmit_skb_list() relies on when it sets its tail pointer (tail = skb->prev). When validate_xmit_xfrm() walks a GSO list and some segments are stolen by async crypto (->xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head ->prev is never updated. If the last segment is the one stolen, the returned head still has ->prev pointing at it, even though it is now owned by the crypto engine and may be freed. validate_xmit_skb_list() later does tail->next = skb, writing through that stale pointer -- a use-after-free. Repoint skb->prev at the last retained segment before returning.

Severity

CRITICAL

CVSS score

9.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-10 13:20:36.540000

Last modified

2026-10-30 13:19:45.277000

View original CVE JSON

{
  "id": "CVE-2026-68426",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-10T13:20:36.540",
  "lastModified": "2026-10-30T13:19:45.277",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix stale skb->prev after async crypto steals a GSO segment\n\nskb_gso_segment() leaves the segment list head with ->prev pointing at\nthe last segment, an invariant validate_xmit_skb_list() relies on when\nit sets its tail pointer (tail = skb->prev).\n\nWhen validate_xmit_xfrm() walks a GSO list and some segments are stolen\nby async crypto (->xmit() returns -EINPROGRESS), those segments are\nunlinked from the list but the head ->prev is never updated.  If the\nlast segment is the one stolen, the returned head still has ->prev\npointing at it, even though it is now owned by the crypto engine and may\nbe freed.  validate_xmit_skb_list() later does tail->next = skb, writing\nthrough that stale pointer -- a use-after-free.\n\nRepoint skb->prev at the last retained segment before returning."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/xfrm/xfrm_device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "4e695742396be18d5291c310a3d7c450959d647a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "4927ab8a8acc8db4fad33e803d1d35e0b16cef83",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "b58731e0570bfd3989999fc2baf9ee4fecd5bec6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "33e1b0d25ca0d2818c635ff80e6aa0d295e08a98",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "bbca7cc3b2b4b10afbfee99b81d9ee78f5423046",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f53c723902d1ac5f0b0a11d7c9dcbff748dde74e",
              "lessThan": "3f4c3919baf0944ad96580467c302bc6c7758b00",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/xfrm/xfrm_device.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.16",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.16",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.42",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "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:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:48:46.371818Z",
          "id": "CVE-2026-68426",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/33e1b0d25ca0d2818c635ff80e6aa0d295e08a98",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3f4c3919baf0944ad96580467c302bc6c7758b00",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4927ab8a8acc8db4fad33e803d1d35e0b16cef83",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4e695742396be18d5291c310a3d7c450959d647a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b58731e0570bfd3989999fc2baf9ee4fecd5bec6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}