CVE-2026-56387

waiting for further signalsZero needs more public information before it can validate it.

GHSA-79v7-r95h-fxr5 ↗EUVD-2026-107173 ↗

no check availablenot proven exploitable
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).kevAttacks confirmed in the real world.
Apache Software Foundation Apache bRPC < 1.18.0
fixed in 1.18.0
CWE-789 Memory Allocation with Excessive Size Value
ETK-2026-2316Zero's internal tracking ID, independent of the CVE number., permanent identifier
1h 17msince last run
1h 03mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = cve.org publication
trigger signal (cve.org) +0hwaiting for further signals+1h25m
0
+2h
+4h
+6h
+8h
+10h
+12h

description

Apache bRPC deployments with the RTMP server enabled, and applications that parse untrusted AMF data directly, are affected. An unauthenticated remote attacker able to send RTMP traffic can cause excessive memory allocation or resource consumption using oversized declared AMF string lengths or array counts.

mitigation

Upgrade apache/brpc to version 1.18.0. Configure AMF string and array-size limits appropriate for the deployment, and restrict untrusted access to RTMP services where possible.

fixed in 1.18.0

check
no
exploit
no
automationDeterministic: a check that runs on its own, the same request on every target. Contextual: an agentic technique that needs to be applied per target, for bugs that depend on contextual flows.
–
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
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EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
–
agent run time
1h 03m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-21 11:39Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
–
Δ to kevAttacks confirmed in the real world.
–

outcome

No artifact: an exploit or check was attempted but could not be produced at this moment.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

  1. 2026-10-21 11:39Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-56387

{
  "etk_id": "ETK-2026-2316",
  "cve_id": "CVE-2026-56387",
  "display_id": "CVE-2026-56387",
  "ghsa_id": "GHSA-79v7-r95h-fxr5",
  "euvd_id": "EUVD-2026-107173",
  "status": "published",
  "anchor_state": "anchored",
  "title": "RTMP AMF resource exhaustion in Apache bRPC",
  "summary": "Apache bRPC deployments with the RTMP server enabled, and applications that parse untrusted AMF data directly, are affected. An unauthenticated remote attacker able to send RTMP traffic can cause excessive memory allocation or resource consumption using oversized declared AMF string lengths or array counts.",
  "mitigation": "Upgrade apache/brpc to version 1.18.0. Configure AMF string and array-size limits appropriate for the deployment, and restrict untrusted access to RTMP services where possible.",
  "vendor": "Apache Software Foundation",
  "product": "Apache bRPC",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, < 1.18.0"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "1.18.0"
      ],
      "package_name": "apache/brpc",
      "purl": null
    }
  ],
  "cwes": [
    789
  ],
  "cvss_score": null,
  "cvss_src": null,
  "cvss_vector": null,
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "deterministic",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 62.988388666666665,
  "t0_at": "2026-10-21T11:39:11.225000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-21T11:39:11.225000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-21T11:39:11.225000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-56387"
    }
  }
}

published 2026-10-21 12:01Z
last change 2026-10-21 14:01Z

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