6.1

CVE-2025-15265: Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR)

Analyzed
AliasesGHSA-6738-r8g5-qwp3
Published 15-01-2026Last modified 15-01-2026

Vulnerability summary

CVE-2025-15265 is a medium (CVSS 6.1) vulnerability in svelte. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.1% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Routine

Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.1/10
010
Medium · v3.1 (NVD)
EPSS score
0.35%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Timeline

  1. 15-01-2026
    PublishedVulnerability first disclosed.
  2. 15-01-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

Decrease -0.01 pp

From 0.35% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (fluidattacks.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Npm1 product
  • svelte≥ 5.46.0, < 5.46.4
Svelte1 product

2 vendors · 2 products

References

6 links