ux-live-component: Format-less date LiveProps parsed with the permissive DateTime constructor

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-49208: 0.41% estimated exploitation activity in the next 30 days; percentile 35.48 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description When a #[LiveProp] is typed as a DateTimeInterface and no explicit format is configured, Symfony\UX\LiveComponent\LiveComponentHydrator::hydrateObjectValue() falls back to new $className($value). The DateTime / DateTimeImmutable constructors accept relative strings such as "now", "tomorrow", or "+10 years", so a writable, format-less date prop can be pushed to an arbitrary point in time by the client. Components that rely on a date prop to gate time-based business logic can be moved past those checks by a frontend payload that no maintainer would consider a valid date. Resolution hydrateObjectValue() now parses format-less date props strictly with createFromFormat(DateTimeInterface::RFC3339, ...), matching the format already emitted by dehydrateObjectValue(). Normal round-trips are unaffected; only inputs that aren't valid RFC 3339 are now rejected, which is consistent with how a format-configured prop already behaved. The patch for this issue is available here for branch…

Published by the source

19 Jun 2026, 19:23 UTC

Last modified by the source

19 Jun 2026, 19:23 UTC

Source last checked

26 Oct 2026, 14:49 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-89g7-22c8-3j23

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# Patch Next advisory brief: CVE-2026-49208

Advisory: ux-live-component: Format-less date LiveProps parsed with the permissive DateTime constructor
IDs: CVE-2026-49208, GHSA-89g7-22c8-3j23
Record: https://patchnext.com/advisories/cve-2026-49208 (revision 1, source checked 26 Oct 2026, 14:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: symfony/ux-live-component 3.1.0, 2.36.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist symfony/ux-live-component: affected >= 2.8.0, < 2.36.0; >= 3.0.0, < 3.1.0; fixed in 3.1.0, 2.36.0

## Suggested inspection (read-only)
- Packagist symfony/ux-live-component: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on symfony/ux-live-component.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-89g7-22c8-3j23 (GitHub-reviewed advisory GHSA-89g7-22c8-3j23 lists affected ranges: Packagist symfony/ux-live-component >=2.8.0 =3.0.0 <3.1.0)

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