CVE-2026-121971
waiting for further signalsZero needs more public information before it can validate it.GHSA-wgw5-9p87-vhvp ↗EUVD-2026-117008 ↗
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.
sensiolabs symfony <5.4.56; >=6; <6.4.50; >=7; <7.4.23; >=8; <8.1.11
fixed in 5.4.56, 6.4.50, 7.4.23, 8.1.11
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
ETK-2026-3527Zero's internal tracking ID, independent of the CVE number., permanent identifier
pkg:composer/symfony/http-client
pkg:composer/symfony/symfony
4h 30msince last run
11mAI analysisAnalysis: how long the AI spent reversing this signal.
description
Symfony HttpClient's ScopingHttpClient is affected when a scoped client uses a base URI together with default authentication settings. An attacker able to influence the start of a requested URL may cause those credentials to be included in a request sent to an external origin.
mitigation
Upgrade symfony/http-client to 5.4.56, 6.4.50, 7.4.23, or 8.1.11, as applicable. Until upgraded, do not pass attacker-controlled URLs to scoped clients configured with credentials.
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
11m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-11-04 17:43Z
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 17:43Zcve_org: trigger signal, started the run
this entry in the feed
GET /api/v1/feed/CVE-2026-121971
{ "etk_id": "ETK-2026-3527", "cve_id": "CVE-2026-121971", "display_id": "CVE-2026-121971", "ghsa_id": "GHSA-wgw5-9p87-vhvp", "euvd_id": "EUVD-2026-117008", "status": "published", "anchor_state": "anchored", "title": "Cross-origin credential disclosure in Symfony ScopingHttpClient", "summary": "Symfony HttpClient's ScopingHttpClient is affected when a scoped client uses a base URI together with default authentication settings. An attacker able to influence the start of a requested URL may cause those credentials to be included in a request sent to an external origin.", "mitigation": "Upgrade symfony/http-client to 5.4.56, 6.4.50, 7.4.23, or 8.1.11, as applicable. Until upgraded, do not pass attacker-controlled URLs to scoped clients configured with credentials.", "vendor": "sensiolabs", "product": "symfony", "affected": [ { "affected_notes": [], "affected_ranges": [ "<5.4.56" ], "ecosystem": "composer", "fixed_versions": [ "5.4.56" ], "package_name": "symfony/http-client", "purl": "pkg:composer/symfony/http-client" }, { "affected_notes": [], "affected_ranges": [ ">=6", "<6.4.50" ], "ecosystem": "composer", "fixed_versions": [ "6.4.50" ], "package_name": "symfony/http-client", "purl": "pkg:composer/symfony/http-client" }, { "affected_notes": [], "affected_ranges": [ ">=7", "<7.4.23" ], "ecosystem": "composer", "fixed_versions": [ "7.4.23" ], "package_name": "symfony/http-client", "purl": "pkg:composer/symfony/http-client" }, { "affected_notes": [], "affected_ranges": [ ">=8", "<8.1.11" ], "ecosystem": "composer", "fixed_versions": [ "8.1.11" ], "package_name": "symfony/http-client", "purl": "pkg:composer/symfony/http-client" }, { "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", "<6.4.50" ], "ecosystem": "composer", "fixed_versions": [ "6.4.50" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=7", "<7.4.23" ], "ecosystem": "composer", "fixed_versions": [ "7.4.23" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" }, { "affected_notes": [], "affected_ranges": [ ">=8", "<8.1.11" ], "ecosystem": "composer", "fixed_versions": [ "8.1.11" ], "package_name": "symfony/symfony", "purl": "pkg:composer/symfony/symfony" } ], "cwes": [ 200 ], "cvss_score": 8.2, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/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": 10.996920183333334, "t0_at": "2026-11-04T17:43:34.806000+00:00", "signals": { "trigger_signal": { "at": "2026-11-04T17:43:34.806000+00:00", "days": 0, "is_lower_bound": false, "measured_at": "2026-11-04T17:43:34.806000+00:00", "url": "https://www.cve.org/CVERecord?id=CVE-2026-121971" } } }
published 2026-11-04 18:04Z
last change 2026-11-04 21:53Z
Need the technical details behind an entry?
Every entry here shows what we attempted and when. The technical details, the generated exploit that fired it and the evidence behind the verdict are not public. Tell us about your use case and we’ll get back to you about extended API access.