CVE-2026-109413
waiting for further signalsZero needs more public information before it can validate it.GHSA-2v3c-qxhr-7vpv ↗EUVD-2026-102109 ↗
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.
composer:symfony/yaml <5.4.54; >=6; <6.4.45; >=7; <7.4.18; >=8; <8.1.6
fixed in 5.4.54, 6.4.45, 7.4.18, 8.1.6
CWE-674 Uncontrolled Recursion
ETK-2026-1666Zero's internal tracking ID, independent of the CVE number., permanent identifier
pkg:composer/symfony/yaml
pkg:composer/symfony/symfony
6d 05h 22msince last run
15mAI analysisAnalysis: how long the AI spent reversing this signal.
description
Symfony YAML releases before 5.4.54, 6.4.45, 7.4.18, and 8.1.6 can exhaust the PHP stack while parsing deeply nested inline YAML collections. An attacker who can supply YAML to an application may cause a request failure or process crash; endpoints using MapRequestPayload are exposed when YAML is installed and accepted without format restrictions.
mitigation
Upgrade symfony/yaml, or the symfony/symfony metapackage, to 5.4.54, 6.4.45, 7.4.18, or 8.1.6 or later on the corresponding branch. Until upgraded, do not parse untrusted YAML and restrict request endpoints to accepted non-YAML formats.
fixed in 5.4.54, 6.4.45, 7.4.18, 8.1.6
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.
0.51%42nd percentile
agent run time
15m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-15 14:57Z
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
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.
- 2026-10-15 06:58Zghsa: trigger signal, started the run
- 2026-10-15 14:57Zcve.org record for CVE-2026-109413
this entry in the feed
GET /api/v1/feed/CVE-2026-109413
{ "etk_id": "ETK-2026-1666", "cve_id": "CVE-2026-109413", "display_id": "CVE-2026-109413", "ghsa_id": "GHSA-2v3c-qxhr-7vpv", "euvd_id": "EUVD-2026-102109", "status": "published", "anchor_state": "anchored", "title": "Unbounded recursion denial of service in Symfony YAML", "summary": "Symfony YAML releases before 5.4.54, 6.4.45, 7.4.18, and 8.1.6 can exhaust the PHP stack while parsing deeply nested inline YAML collections. An attacker who can supply YAML to an application may cause a request failure or process crash; endpoints using MapRequestPayload are exposed when YAML is installed and accepted without format restrictions.", "mitigation": "Upgrade symfony/yaml, or the symfony/symfony metapackage, to 5.4.54, 6.4.45, 7.4.18, or 8.1.6 or later on the corresponding branch. Until upgraded, do not parse untrusted YAML and restrict request endpoints to accepted non-YAML formats.", "vendor": "composer", "product": "composer:symfony/yaml", "affected": [ { "affected_notes": [], "affected_ranges": [ "<5.4.54" ], "ecosystem": "composer", "fixed_versions": [ "5.4.54" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=6", "<6.4.45" ], "ecosystem": "composer", "fixed_versions": [ "6.4.45" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=7", "<7.4.18" ], "ecosystem": "composer", "fixed_versions": [ "7.4.18" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=8", "<8.1.6" ], "ecosystem": "composer", "fixed_versions": [ "8.1.6" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ "<5.4.54" ], "ecosystem": "composer", "fixed_versions": [ "5.4.54" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=6", "<6.4.45" ], "ecosystem": "composer", "fixed_versions": [ "6.4.45" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=7", "<7.4.18" ], "ecosystem": "composer", "fixed_versions": [ "7.4.18" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=8", "<8.1.6" ], "ecosystem": "composer", "fixed_versions": [ "8.1.6" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" } ], "cwes": [ 674 ], "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": 0.0051, "epss_percentile": 0.4205, "epss_asof": "2026-10-20", "automation": "contextual", "check": false, "check_confidence_basis": null, "exploit": false, "pipeline_minutes": 14.623166483333334, "t0_at": "2026-10-15T14:57:00.211000+00:00", "signals": { "trigger_signal": { "at": "2026-10-15T06:58:41+00:00", "days": -0.33216679398148147, "is_lower_bound": false, "measured_at": "2026-10-15T14:57:00.211000+00:00", "url": "https://github.com/symfony/symfony/security/advisories/GHSA-2v3c-qxhr-7vpv" } } }
published 2026-10-15 10:02Z
last change 2026-10-21 19:22Z
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