CVE-2026-31636

Estado: AnalizadaCrítica (9.1)—

In the Linux kernel, the following vulnerability has been resolved:

rxrpc: fix RESPONSE authenticator parser OOB read

rxgk_verify_authenticator() copies auth_len bytes into a temporary buffer and then passes p + auth_len as the parser limit to rxgk_do_verify_authenticator(). Since p is a __be32 *, that inflates the parser end pointer by a factor of four and lets malformed RESPONSE authenticators read past the kmalloc() buffer.

Decoded from the original latest-net reproduction logs with scripts/decode_stacktrace.sh:

Convert the byte count to __be32 units before constructing the parser limit.

Detalles técnicos trazas, registros y código del informe original

BUG: KASAN: slab-out-of-bounds in rxgk_verify_response()
Call Trace:
 dump_stack_lvl() [lib/dump_stack.c:123]
 print_report() [mm/kasan/report.c:379 mm/kasan/report.c:482]
 kasan_report() [mm/kasan/report.c:597]
 rxgk_verify_response()
   [net/rxrpc/rxgk.c:1103 net/rxrpc/rxgk.c:1167
    net/rxrpc/rxgk.c:1274]
 rxrpc_process_connection()
   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364
    net/rxrpc/conn_event.c:386]
 process_one_work() [kernel/workqueue.c:3281]
 worker_thread()
   [kernel/workqueue.c:3353 kernel/workqueue.c:3440]
 kthread() [kernel/kthread.c:436]
 ret_from_fork() [arch/x86/kernel/process.c:164]

Allocated by task 54:
 rxgk_verify_response()
   [include/linux/slab.h:954 net/rxrpc/rxgk.c:1155
    net/rxrpc/rxgk.c:1274]
 rxrpc_process_connection()
   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364
    net/rxrpc/conn_event.c:386]

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Puntuación base: 9.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.63%
Percentil entre todas las CVEs puntuadas: 49
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access75 %
Impacto principalT1005 Data from Local Systemcollection85 %

Vulnerabilidad OOB read en parser remoto sin autenticación (AV:N/PR:N). Lee memoria fuera de límites; no ejecución de código demostrada.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Filter Network Traffic Application Isolation and Sandboxing

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-125

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-31636",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
              "lessThan": "7875f3d9777bd4e9892c4db830571ab8ac2044c0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
              "lessThan": "20a188775a9a9982d1987e12660d9b44b40a6c99",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
              "lessThan": "3e3138007887504ee9206d0bfb5acb062c600025",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/rxrpc/rxgk.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.23",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19.13",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/rxrpc/rxgk.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-04-24T15:16:42.920",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/20a188775a9a9982d1987e12660d9b44b40a6c99",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3e3138007887504ee9206d0bfb5acb062c600025",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7875f3d9777bd4e9892c4db830571ab8ac2044c0",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: fix RESPONSE authenticator parser OOB read\n\nrxgk_verify_authenticator() copies auth_len bytes into a temporary\nbuffer and then passes p + auth_len as the parser limit to\nrxgk_do_verify_authenticator(). Since p is a __be32 *, that inflates the\nparser end pointer by a factor of four and lets malformed RESPONSE\nauthenticators read past the kmalloc() buffer.\n\nDecoded from the original latest-net reproduction logs with\nscripts/decode_stacktrace.sh:\n\nBUG: KASAN: slab-out-of-bounds in rxgk_verify_response()\nCall Trace:\n dump_stack_lvl() [lib/dump_stack.c:123]\n print_report() [mm/kasan/report.c:379 mm/kasan/report.c:482]\n kasan_report() [mm/kasan/report.c:597]\n rxgk_verify_response()\n   [net/rxrpc/rxgk.c:1103 net/rxrpc/rxgk.c:1167\n    net/rxrpc/rxgk.c:1274]\n rxrpc_process_connection()\n   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364\n    net/rxrpc/conn_event.c:386]\n process_one_work() [kernel/workqueue.c:3281]\n worker_thread()\n   [kernel/workqueue.c:3353 kernel/workqueue.c:3440]\n kthread() [kernel/kthread.c:436]\n ret_from_fork() [arch/x86/kernel/process.c:164]\n\nAllocated by task 54:\n rxgk_verify_response()\n   [include/linux/slab.h:954 net/rxrpc/rxgk.c:1155\n    net/rxrpc/rxgk.c:1274]\n rxrpc_process_connection()\n   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364\n    net/rxrpc/conn_event.c:386]\n\nConvert the byte count to __be32 units before constructing the parser\nlimit."
    }
  ],
  "lastModified": "2026-06-17T10:34:08.277",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "EAE31F43-AAC5-4801-B2B2-119D62A532A2",
              "versionEndExcluding": "6.18.23",
              "versionStartIncluding": "6.16.1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1490EF9B-9080-481C-8D22-1306AAE664E4",
              "versionEndExcluding": "6.19.13",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6238B17D-C12B-458F-A138-97039BFC4595"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}