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CVE-2026-18418

Status: Awaiting AnalysisLow (3.4)—
Severity3.4Low · CVSS 3.1
Exploitation probability0.11 %higher than 1% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

The zbus proxy agent IPC backend in subsys/zbus/proxy_agent/zbus_proxy_agent_ipc.c logged the channel name of a rejected inter-domain frame with a plain %s conversion. The frame type struct zbus_proxy_msg carries a fixed-size channel_name[] array as its last member, and nothing in the transport guarantees the array is NUL-terminated. The only code that verifies termination is zbus_proxy_agent_receive_cb() in subsys/zbus/proxy_agent/zbus_proxy_agent.c, which rejects the frame in precisely those cases — so the warning printed a non-terminated buffer exactly on the error paths where the name had been found invalid (or, for an invalid message_size, had not been inspected at all).

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Any peer domain able to place a frame of sizeof(struct zbus_proxy_msg) bytes on the bound ipc_service endpoint can trigger it, by sending a frame with an out-of-range message_size or with channel_name[] containing no NUL byte. Reaching the code requires CONFIG_ZBUS_PROXY_AGENT_IPC and logging built at warning level or above (the default), and requires control over the firmware of the peer domain — typically a second core on the same SoC.

The resulting strlen() inside the log packager walks past the end of the frame object until it finds a zero byte. With the icmsg backend the frame lives in a stack buffer of the IPC work-queue thread, so bytes of that thread's stack are rendered into the log message; with the rpmsg backends the scan continues through the shared vring memory. Impact is bounded to disclosure of a small amount of adjacent memory into the receiving domain's log sink, plus a possible fatal fault if the scan leaves a mapped region; the log packager's own -ENOSPC bound prevents the overrun from becoming a write. The fix bounds the conversion with %.*s and MIN(msg->channel_name_len, sizeof(msg->channel_name)).

CVSS

Base score
3.4
Version
3.1
Vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:L

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.11 %
Percentile among all scored CVEs
1
Score date
10/21/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

Vulnerabilidad local (AV:L, PR:H) que expone información adyacente en memoria (stack/vring) mediante lectura de buffer sin terminación NUL. Requiere control del firmware del dominio par, típicamente segundo núcleo en SoC.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Threat Intelligence ProgramFilter Network TrafficExecution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate Software

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Zephyrproject — ZephyrAI

CWEs

References

Show 2 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-18418",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-18418",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-15T17:51:25.324466Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "vulnerabilities@zephyrproject.org",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.4,
          "attackVector": "LOCAL",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "LOW",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.5,
        "exploitabilityScore": 0.8
      }
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  "affected": [
    {
      "source": "vulnerabilities@zephyrproject.org",
      "affectedData": [
        {
          "vendor": "zephyrproject",
          "product": "zephyr",
          "versions": [
            {
              "status": "affected",
              "version": "4.4.0",
              "lessThan": "4.4.2",
              "versionType": "semver"
            }
          ],
          "packageName": "zephyr",
          "programFiles": [
            "subsys/zbus/proxy_agent/zbus_proxy_agent_ipc.c"
          ],
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
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            }
          ]
        }
      ]
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  "published": "2026-10-11T18:16:58.113",
  "references": [
    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/fc065f79a568a6c6cc14b89795bd60e5eabd6f02",
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      "source": "vulnerabilities@zephyrproject.org"
    }
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  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
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      "description": [
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          "lang": "en",
          "value": "CWE-125"
        }
      ]
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The zbus proxy agent IPC backend in subsys/zbus/proxy_agent/zbus_proxy_agent_ipc.c logged the channel name of a rejected inter-domain frame with a plain %s conversion. The frame type struct zbus_proxy_msg carries a fixed-size channel_name[] array as its last member, and nothing in the transport guarantees the array is NUL-terminated. The only code that verifies termination is zbus_proxy_agent_receive_cb() in subsys/zbus/proxy_agent/zbus_proxy_agent.c, which rejects the frame in precisely those cases — so the warning printed a non-terminated buffer exactly on the error paths where the name had been found invalid (or, for an invalid message_size, had not been inspected at all).\n\nAny peer domain able to place a frame of sizeof(struct zbus_proxy_msg) bytes on the bound ipc_service endpoint can trigger it, by sending a frame with an out-of-range message_size or with channel_name[] containing no NUL byte. Reaching the code requires CONFIG_ZBUS_PROXY_AGENT_IPC and logging built at warning level or above (the default), and requires control over the firmware of the peer domain — typically a second core on the same SoC.\n\nThe resulting strlen() inside the log packager walks past the end of the frame object until it finds a zero byte. With the icmsg backend the frame lives in a stack buffer of the IPC work-queue thread, so bytes of that thread's stack are rendered into the log message; with the rpmsg backends the scan continues through the shared vring memory. Impact is bounded to disclosure of a small amount of adjacent memory into the receiving domain's log sink, plus a possible fatal fault if the scan leaves a mapped region; the log packager's own -ENOSPC bound prevents the overrun from becoming a write. The fix bounds the conversion with %.*s and MIN(msg->channel_name_len, sizeof(msg->channel_name))."
    }
  ],
  "lastModified": "2026-10-15T19:17:36.960",
  "sourceIdentifier": "vulnerabilities@zephyrproject.org"
}