Symfony UX is a JavaScript ecosystem for Symfony. From 2.5.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Controller\BatchActionController::__invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry; because the array size is never bounded, an authenticated client can submit a single _batch request containing thousands of actions and exhaust CPU, memory, and database connections on the application server. This issue is fixed in versions 2.36.0 and 3.1.0.
CVE-2026-49209
MEDIUMNVD 6.56.5—Trending — 4 sources updated this week
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 77% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(medium)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity65% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 23.5%
- KEV
- Not listed
Published
June 19, 2026
Last Modified
July 20, 2026
Advisory Details (4)
Auto-updated Jul 17, 2026Patch available. Sources: github_release, github, github_commit.
github Patch Available
Denial of service in symfony/ux-live-component via unbounded batch action requests · Advisory · symfony/ux · GitHub
https://github.com/symfony/ux/security/advisories/GHSA-mm82-c99c-h2cfgithub_release Patch Available
v3.1.0
Patch available: symfony/ux v3.1.0
https://github.com/symfony/ux/releases/tag/v3.1.0github_release Patch Available
v2.36.0
Patch available: symfony/ux v2.36.0
https://github.com/symfony/ux/releases/tag/v2.36.0github_commit Patch Available
commit 95e878d5257f (symfony/ux)
Patch available: symfony/ux v2.36.0 (contains commit 95e878d5257f)
https://github.com/symfony/ux/commit/95e878d5257f13d6d652ca95e3ef6bb0934d674fVendor 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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| symfony/ux-live-component | v3.0.0 | 3.1.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× 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.
- 2026-07-23 03:18 UTCEG score recompute▲ 1.20
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-20 17:06 UTCNVD updateCVSS v3 → 6.5
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-17 16:20 UTCEG score recompute▲ 5.30
- 2026-07-17 16:19 UTCMITRE cvelistV5CVSS v3 → 5.3 · CVSS v4 → 5.3 · severity → MEDIUM
- 2026-06-19 19:36 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-770
- CVE-2018-20033EG 9.8CRITICAL
- CVE-2019-11479NVD 7.5EG 9.0EPSS 100%HIGH
- CVE-2019-11478NVD 5.3EG 9.0EPSS 100%MEDIUM
- CVE-2019-10088EG 8.8EPSS 91%HIGH
- CVE-2018-15462EG 8.6HIGH
- CVE-2018-15460EG 8.6HIGH
- CVE-2018-0137EG 8.6HIGH
- CVE-2008-5180NVD 5.3EG 7.9EPSS 99%MEDIUM
- CVE-2019-10094EG 7.8HIGH
- CVE-2018-16865EG 7.8HIGH
Frequently asked(5)
What is CVE-2026-49209?
CVE-2026-49209 is a medium vulnerability published on June 19, 2026. Symfony UX is a JavaScript ecosystem for Symfony. From 2.5.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Controller\BatchActionController::invoke() iterates over the client-supplied actions array and issues a full HttpKernel sub-request for each entry; because the array size is never bounded,…
When was CVE-2026-49209 disclosed?
CVE-2026-49209 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on July 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49209 actively exploited?
CVE-2026-49209 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 23.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-49209?
CVE-2026-49209 has a CVSS v3 base score of 6.5 (NVD).
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
Is Your Infrastructure Affected by CVE-2026-49209?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.