Vulnerability-Lookup

GHSA-5HCH-WGMX-FJG3

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

rxrpc: rxrpc_verify_data ensure rx_dec_buffer alloc

rxrpc_recvmsg_data() calls rxrpc_verify_data() whenever the rxrpc_call.rx_dec_buffer is unallocated and assumes that upon successful return that rx_dec_buffer must be allocated. However, rxrpc_verify_data() does not request an allocation if the rxrpc_skb_priv.len is zero.

In addition, failure to allocate rx_dec_buffer will result in a call to skb_copy_bits() with a NULL destination which can trigger a NULL pointer dereference.

To prevent these issues rxrpc_verify_data() is modified to always attempt to allocate the rxrpc_call.rx_dec_buffer if it is NULL.

This issue was identified with assistance of a private sashiko instance.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74435"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:45Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: rxrpc_verify_data ensure rx_dec_buffer alloc\n\nrxrpc_recvmsg_data() calls rxrpc_verify_data() whenever the\nrxrpc_call.rx_dec_buffer is unallocated and assumes that upon\nsuccessful return that rx_dec_buffer must be allocated.\nHowever, rxrpc_verify_data() does not request an allocation if\nthe rxrpc_skb_priv.len is zero.\n\nIn addition, failure to allocate rx_dec_buffer will result in a\ncall to skb_copy_bits() with a NULL destination which can\ntrigger a NULL pointer dereference.\n\nTo prevent these issues rxrpc_verify_data() is modified to\nalways attempt to allocate the rxrpc_call.rx_dec_buffer if it\nis NULL.\n\nThis issue was identified with assistance of a private\nsashiko instance.",
  "id": "GHSA-5hch-wgmx-fjg3",
  "modified": "2026-08-17T06:33:45Z",
  "published": "2026-08-15T06:32:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74435"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16c8ae9735c5bd7e54dd7478d6348e0fc860842d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6563b4eb38c35d75892445bcf8aacdc29914821c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bbede0afced346b24e4fbde0c68cf12980ba948"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a962bc8508592c4d51092edac68579bd8b18fe44"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d3b642cf95d48234590cc91450d8705a9bf6b540"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74435 (GCVE-0-2026-74435)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:59 – Updated: 2026-08-17 05:47

Title

rxrpc: rxrpc_verify_data ensure rx_dec_buffer alloc

Summary

In the Linux kernel, the following vulnerability has been resolved: rxrpc: rxrpc_verify_data ensure rx_dec_buffer alloc rxrpc_recvmsg_data() calls rxrpc_verify_data() whenever the rxrpc_call.rx_dec_buffer is unallocated and assumes that upon successful return that rx_dec_buffer must be allocated. However, rxrpc_verify_data() does not request an allocation if the rxrpc_skb_priv.len is zero. In addition, failure to allocate rx_dec_buffer will result in a call to skb_copy_bits() with a NULL destination which can trigger a NULL pointer dereference. To prevent these issues rxrpc_verify_data() is modified to always attempt to allocate the rxrpc_call.rx_dec_buffer if it is NULL. This issue was identified with assistance of a private sashiko instance.

Severity

7.5 (High)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/8bbede0afced346b2…
https://git.kernel.org/stable/c/6563b4eb38c35d758…
https://git.kernel.org/stable/c/d3b642cf95d482345…
https://git.kernel.org/stable/c/a962bc8508592c4d5…
https://git.kernel.org/stable/c/16c8ae9735c5bd7e5…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a05bf6d9e621fa71e89ccebe3047ba45218d7b38 , < 8bbede0afced346b24e4fbde0c68cf12980ba948 (git) Affected: b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5 , < 6563b4eb38c35d75892445bcf8aacdc29914821c (git) Affected: 46cb765e2e5ad52303ea157e10d370bb6b7acbbf , < d3b642cf95d48234590cc91450d8705a9bf6b540 (git) Affected: d2bc90cf6c75cb96d2ce549be6c35efa3099d25b , < a962bc8508592c4d51092edac68579bd8b18fe44 (git) Affected: d2bc90cf6c75cb96d2ce549be6c35efa3099d25b , < 16c8ae9735c5bd7e54dd7478d6348e0fc860842d (git) Affected: c580087743712112778a06d65a4074053072d7bf (git) Affected: 6.6.143 , < 6.6.145 (semver) Affected: 6.12.93 , < 6.12.97 (semver) Affected: 6.18.35 , < 6.18.40 (semver) Affected: 7.0.11 , < 7.1 (semver)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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        {
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          "programFiles": [
            "net/rxrpc/recvmsg.c"
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          "scenarios": [
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              "value": "AV:N - RxRPC runs over UDP/IP; a remote peer can deliver crafted DATA packets that are queued on the receive path and later processed in rxrpc_verify_data() via recvmsg/kernel_recv_data, with no local access required.\nAC:L - An attacker can reliably trigger the bug by sending a zero-length RxRPC DATA packet (header-only skb so sp-\u003elen==0) to a listening service; no races or victim-specific state are needed beyond an active RxRPC/AFS endpoint.\nPR:N - Incoming DATA packets are accepted and queued on new calls before Kerberos authentication completes, so an unauthenticated remote attacker can reach the vulnerable recvmsg path on internet-facing AFS/RxRPC servers without any local privileges.\nUI:N - On AFS/RxRPC servers the kernel automatically receives network DATA, queues it, and invokes rxrpc_kernel_recv_data through service callbacks; exploitation requires no victim user action such as mounting a filesystem or opening a file.\nS:U - The flaw causes a kernel NULL pointer dereference during in-kernel packet processing on the same host running the RxRPC/AFS service; it does not cross a VM, container, or IOMMU security boundary.\nC:N - The failure mode is a NULL pointer dereference in skb_copy_bits()/subsequent recvmsg handling when rx_dec_buffer was never allocated; this is a pure crash path with no demonstrated or plausible arbitrary kernel memory read or information disclosure.\nI:N - No memory corruption, arbitrary write, or code-execution primitive is introduced; the bug dereferences a NULL decryption buffer during receive processing and results in kernel oops/panic rather than controlled data modification.\nA:H - A successful trigger causes a kernel NULL pointer dereference during recvmsg data verification/decryption, which can oops or panic the host and deny service to all workloads on affected AFS/RxRPC servers until reboot."
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74435",
    "datePublished": "2026-08-15T05:59:34.073Z",
    "dateReserved": "2026-08-15T05:44:03.896Z",
    "dateUpdated": "2026-08-17T05:47:09.898Z",
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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.

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.

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GHSA-5HCH-WGMX-FJG3

CVE-2026-74435 (GCVE-0-2026-74435)

Tags

Sightings

Nomenclature