CVE-2026-49209

LOWPre-NVD 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: —CVSS: —Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

symfony/ux-live-component: Denial of service via unbounded batch action requests

Description

Symfony\UX\LiveComponent\Controller\BatchActionController::__invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry (event subscribers, validators, Doctrine, rendering). The array size is never bounded, so an authenticated client can submit a single _batch request containing thousands of actions and exhaust CPU, memory, and database connections on the application server.

Resolution

BatchActionController now enforces an upper bound of 50 actions per _batch request (MAX_ACTIONS_PER_BATCH) and rejects larger payloads up front with a BadRequestHttpException. The matching JavaScript backend was also updated to split larger client-side batches into multiple requests so legitimate usage isn't affected.

The patch for this issue is available here for branch 2.x (and forward-ported to 3.x).

Credits

Symfony would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.

CVSS v3
—
EG Score
0.0(none)
EPSS
—
KEV
Not listed

Published

June 19, 2026

Last Modified

June 19, 2026

Vendor Advisories for CVE-2026-49209(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
symfony/ux-live-componentv3.0.03.1.0—

Data Freshness Timeline

(refreshed 0× in last 7d / 1× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-06-19 19:36 UTCEG score recompute

Frequently asked(3)

What is CVE-2026-49209?
CVE-2026-49209 is a low vulnerability published on June 19, 2026. symfony/ux-live-component: Denial of service via unbounded batch action requests Description Symfony\UX\LiveComponent\Controller\BatchActionController::invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry (event subscribers, validators,…
When was CVE-2026-49209 disclosed?
CVE-2026-49209 was first published in the National Vulnerability Database on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
How do I remediate CVE-2026-49209?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49209, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-49209

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