CVE-2026-115506

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

GHSA-j83x-34mv-v962 ↗EUVD-2026-108338 ↗

no check availablenot proven exploitable
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).−219dkevAttacks confirmed in the real world.
libexpat <= 2.9.0
CWE-776 Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
ETK-2026-2495Zero's internal tracking ID, independent of the CVE number., permanent identifier
1h 26msince last run
14mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = cve.org publication
public poc−7.2motrigger signal (cve.org) +0mowaiting for further signals+0.0mo
−6mo
−3mo

description

libexpat through 2.9.0 can consume excessive CPU while parsing XML documents with deeply nested entity expansions. An attacker needs the ability to provide XML that the affected application parses.

mitigation

Restrict parsing of untrusted XML and disable or reject DTD and entity expansion where the application configuration allows it. Apply an upstream fixed release when one is published; no fixed version is recorded in the advisory.

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.
contextual
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
no
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
–
agent run time
14m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-22 19:14Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
−219d
Δ to kevAttacks confirmed in the real world.
–

outcome

Contextual: an exploit technique exists, but no deterministic check could cover this one.

source signals

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

  1. 2026-10-22 19:14Z
    cve_org: trigger signal, started the run
  2. 2026-10-22 21:06Z

this entry in the feed

GET /api/v1/feed/CVE-2026-115506

{
  "etk_id": "ETK-2026-2495",
  "cve_id": "CVE-2026-115506",
  "display_id": "CVE-2026-115506",
  "ghsa_id": "GHSA-j83x-34mv-v962",
  "euvd_id": "EUVD-2026-108338",
  "status": "published",
  "anchor_state": "anchored",
  "title": "XML entity expansion denial of service in libexpat",
  "summary": "libexpat through 2.9.0 can consume excessive CPU while parsing XML documents with deeply nested entity expansions. An attacker needs the ability to provide XML that the affected application parses.",
  "mitigation": "Restrict parsing of untrusted XML and disable or reject DTD and entity expansion where the application configuration allows it. Apply an upstream fixed release when one is published; no fixed version is recorded in the advisory.",
  "vendor": "libexpat",
  "product": "libexpat",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, <= 2.9.0"
      ],
      "ecosystem": null,
      "fixed_versions": [],
      "package_name": "libexpat",
      "purl": null
    }
  ],
  "cwes": [
    776
  ],
  "cvss_score": 8.7,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 13.84029965,
  "t0_at": "2026-10-22T19:14:06.001000+00:00",
  "signals": {
    "public_poc": {
      "at": "2026-03-17T13:05:13+00:00",
      "days": -219.25616899305555,
      "is_lower_bound": false,
      "measured_at": "2026-10-22T19:14:06.001000+00:00",
      "url": "https://github.com/hannob/lololol"
    },
    "trigger_signal": {
      "at": "2026-10-22T19:14:06.001000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-22T19:14:06.001000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-115506"
    }
  }
}

published 2026-10-22 20:39Z
last change 2026-10-22 22:09Z

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