Vulnerability-Lookup

FKIE_CVE-2026-31636

Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-06-17 10:34

Severity

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

Summary

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

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/20a188775a9a9982d1987e12660d9b44b40a6c99	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3e3138007887504ee9206d0bfb5acb062c600025	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7875f3d9777bd4e9892c4db830571ab8ac2044c0	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	6.16
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/rxrpc/rxgk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "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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        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.23",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
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  "cveTags": [],
  "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."
    }
  ],
  "id": "CVE-2026-31636",
  "lastModified": "2026-06-17T10:34:08.277",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-24T15:16:42.920",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/20a188775a9a9982d1987e12660d9b44b40a6c99"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31636 (GCVE-0-2026-31636)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:44 – Updated: 2026-08-05 12:24

Title

rxrpc: fix RESPONSE authenticator parser OOB read

Summary

Severity

9.1 (Critical)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/7875f3d9777bd4e98…
https://git.kernel.org/stable/c/20a188775a9a9982d…
https://git.kernel.org/stable/c/3e3138007887504ee…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a , < 7875f3d9777bd4e9892c4db830571ab8ac2044c0 (git) Affected: 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a , < 20a188775a9a9982d1987e12660d9b44b40a6c99 (git) Affected: 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a , < 3e3138007887504ee9206d0bfb5acb062c600025 (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.23 , ≤ 6.18.* (semver) Unaffected: 6.19.13 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/rxrpc/rxgk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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              "lessThan": "7875f3d9777bd4e9892c4db830571ab8ac2044c0",
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              "versionType": "git"
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        },
        {
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
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              "lessThan": "6.16",
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              "version": "0",
              "versionType": "semver"
            },
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              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.19.13",
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            {
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              "status": "unaffected",
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              "versionType": "original_commit_for_fix"
            }
          ]
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      "cpeApplicability": [
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        }
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            {
              "lang": "en",
              "value": "AV:N - The vulnerable rxgk RESPONSE authenticator parser is reached by network RxRPC packets delivered over UDP to an AF_RXRPC service connection.\nAC:L - There is no race or condition outside the attacker\u0027s control; a peer can initiate the handshake, receive the challenge, and send malformed RESPONSE data to drive the parser.\nPR:N - The packet is processed while the server connection is still in RXRPC_CONN_SERVICE_CHALLENGING, before the connection is accepted as authenticated.\nUI:N - No victim user action is required beyond the RxRPC service being reachable and processing incoming network traffic.\nS:U - The impact remains within the kernel/RxRPC service security authority and does not cross a VM, IOMMU, or comparable scope boundary.\nC:H - The byte-count versus __be32 pointer arithmetic bug lets the parser read well beyond the kmalloc authenticator buffer at attacker-influenced offsets, and the overread is not strictly bounded to a few bytes.\nI:N - The flaw is an out-of-bounds read and does not provide an arbitrary write or control-flow modification primitive.\nA:H - The fix commit documents a KASAN slab-out-of-bounds report in the RESPONSE processing path, and malformed network responses can repeatedly trigger kernel fault/panic behavior."
            }
          ]
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      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:24:00.729Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        },
        {
          "url": "https://git.kernel.org/stable/c/3e3138007887504ee9206d0bfb5acb062c600025"
        }
      ],
      "title": "rxrpc: fix RESPONSE authenticator parser OOB read",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31636",
    "datePublished": "2026-04-24T14:44:50.637Z",
    "dateReserved": "2026-03-09T15:48:24.125Z",
    "dateUpdated": "2026-08-05T12:24:00.729Z",
    "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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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FKIE_CVE-2026-31636

CVE-2026-31636 (GCVE-0-2026-31636)

Tags

Sightings

Nomenclature

Related by attack behaviour