ETK-2026-3492Zero's internal tracking ID, independent of the CVE number.
waiting for further signalsZero needs more public information before it can validate it.no check availablenot proven exploitable
awaiting cvepublic 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 <5.4.56; >=6.0.0; <6.4.50; >=7.0.0; <7.4.23; >=8.0.0; <8.1.11
fixed in 5.4.56, 6.4.50, 7.4.23, 8.1.11
CWE-407 Inefficient Algorithmic Complexity
ETK-2026-3492Zero's internal tracking ID, independent of the CVE number., no cve assigned
pkg:composer/symfony/yaml
pkg:composer/symfony/symfony
2h 04msince last run
17mAI analysisAnalysis: how long the AI spent reversing this signal.
description
Symfony YAML parsing can consume disproportionate CPU time for specially structured documents, allowing an attacker to tie up PHP workers and degrade service availability. Applications are affected when they parse untrusted YAML with default settings; some endpoints using MapRequestPayload may also accept YAML request bodies unless their accepted formats are restricted.
mitigation
Upgrade symfony/yaml, or symfony/symfony, to 5.4.56, 6.4.50, 7.4.23, or 8.1.11 or later in the applicable release line. Restrict request handlers to required formats and do not accept YAML from untrusted clients where it is unnecessary.
fixed in 5.4.56, 6.4.50, 7.4.23, 8.1.11
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
17m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
not published yet
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, not validated: no deterministic check could cover this one, and no technique passed our review.
source signals
Public signals that triggered or updated the pipeline. These are inputs for the deltas above.
- 2026-11-04 11:43Zghsa: trigger signal, started the run
this entry in the feed
GET /api/v1/feed/ETK-2026-3492
{ "etk_id": "ETK-2026-3492", "cve_id": null, "display_id": "ETK-2026-3492", "ghsa_id": "GHSA-hwfg-qwvh-2wfx", "euvd_id": null, "status": "published", "anchor_state": "awaiting_cve", "title": "Algorithmic complexity denial of service in Symfony YAML parser", "summary": "Symfony YAML parsing can consume disproportionate CPU time for specially structured documents, allowing an attacker to tie up PHP workers and degrade service availability. Applications are affected when they parse untrusted YAML with default settings; some endpoints using MapRequestPayload may also accept YAML request bodies unless their accepted formats are restricted.", "mitigation": "Upgrade symfony/yaml, or symfony/symfony, to 5.4.56, 6.4.50, 7.4.23, or 8.1.11 or later in the applicable release line. Restrict request handlers to required formats and do not accept YAML from untrusted clients where it is unnecessary.", "vendor": "composer", "product": "composer:symfony/yaml", "affected": [ { "affected_notes": [], "affected_ranges": [ "<5.4.56" ], "ecosystem": "composer", "fixed_versions": [ "5.4.56" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=6.0.0", "<6.4.50" ], "ecosystem": "composer", "fixed_versions": [ "6.4.50" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=7.0.0", "<7.4.23" ], "ecosystem": "composer", "fixed_versions": [ "7.4.23" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ ">=8.0.0", "<8.1.11" ], "ecosystem": "composer", "fixed_versions": [ "8.1.11" ], "package_name": "symfony/yaml", "purl": "pkg:composer/symfony/yaml" }, { "affected_notes": [], "affected_ranges": [ "<5.4.56" ], "ecosystem": "composer", "fixed_versions": [ "5.4.56" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=6.0.0", "<6.4.50" ], "ecosystem": "composer", "fixed_versions": [ "6.4.50" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=7.0.0", "<7.4.23" ], "ecosystem": "composer", "fixed_versions": [ "7.4.23" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=8.0.0", "<8.1.11" ], "ecosystem": "composer", "fixed_versions": [ "8.1.11" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" } ], "cwes": [ 407 ], "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": 17.33651095, "t0_at": null, "signals": { "trigger_signal": { "at": "2026-11-04T11:43:34+00:00", "days": -0.08038264836805556, "is_lower_bound": true, "measured_at": "2026-11-04T13:39:19.095331+00:00", "url": "https://github.com/symfony/symfony/security/advisories/GHSA-hwfg-qwvh-2wfx" } } }
published 2026-11-04 11:55Z
last change 2026-11-04 13:33Z
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