Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Util\ChildComponentPartialRenderer::createHtml() interpolates the client-controlled children[id].tag value from LiveComponentSubscriber and InterceptChildComponentRenderSubscriber directly into HTML as a tag name without escaping or validation, allowing arbitrary HTML, including tags, on any Live Component re-render that contains at least one child component. This issue is fixed in versions 2.36.0 and 3.1.0.
CVE-2026-49210
MEDIUMNVD 6.16.1—Trending — 4 sources updated this week
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 91% 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
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EG Risk
- 28(Track)EG Risk 28/100SSVC: 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 computedSeverity61% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 9.3%
- KEV
- Not listed
Published
June 19, 2026
Last Modified
July 20, 2026
References (4)
- security-advisories@githubhttps://github.com/symfony/ux/commit/fbc5e9a1bda7e4556be21bb1d970f382760ed9a9
- security-advisories@githubhttps://github.com/symfony/ux/releases/tag/v2.36.0
- security-advisories@githubhttps://github.com/symfony/ux/releases/tag/v3.1.0
- security-advisories@githubhttps://github.com/symfony/ux/security/advisories/GHSA-38x5-rcv4-xf7x
Vendor Advisories for CVE-2026-49210(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▲ 3.80
- 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 → 6.1 · severity → MEDIUM
- 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▲ 2.30
- 2026-07-17 16:19 UTCMITRE cvelistV5CVSS v3 → 2.3 · CVSS v4 → 2.3 · severity → LOW
- 2026-06-19 19:36 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-49210?
CVE-2026-49210 is a medium vulnerability published on June 19, 2026. Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Util\ChildComponentPartialRenderer::createHtml() interpolates the client-controlled children[id].tag value from LiveComponentSubscriber and InterceptChildComponentRenderSubscriber directly…
When was CVE-2026-49210 disclosed?
CVE-2026-49210 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-2026-49210 actively exploited?
CVE-2026-49210 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 9.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-49210?
CVE-2026-49210 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-49210?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49210, 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-2026-49210
Is Your Infrastructure Affected by CVE-2026-49210?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.