to terminate the script and inject arbitrary JavaScript. This enables remote script execution in users' browsers, wi","mainEntity":{"@type":"Thing","name":"CVE-2025-15265","identifier":"CVE-2025-15265","description":"Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)"},"isPartOf":{"@type":"WebSite","name":"VulnTracker","url":"https://vulntracker.io"}}

CVE-2025-15265

Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)

MEDIUM
6.1
CVSS Score
Published: January 15, 2026 at 07:59 PM UTC
Updated: June 17, 2026 at 08:37 AM UTC
1 product affected across 1 vendorSvelte

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

An SSR XSS exists in async hydration when attacker‑controlled keys are passed to hydratable. The key is embedded inside a <script> block without HTML‑safe escaping, allowing </script> to terminate the script and inject arbitrary JavaScript. This enables remote script execution in users' browsers, with potential for session theft and account compromise. This issue affects Svelte: from 5.46.0 before 5.46.3.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.46.0 ≤ v < 5.46.35.46.0
Affected range stops below 5.46.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Third Party AdvisoryPatchExploit
Source: cverecord
https://fluidattacks.com/advisories/lydian
Vendor AdvisoryThird Party Advisory
Source: cverecord
https://github.com/sveltejs/svelte/security/advisories/GHSA-6738-r8g5-qwp3

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

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