How severe is CVE-2025-15265?

CVE-2025-15265 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-15265 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-15265?

CVE-2025-15265 affects Svelte. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-15265?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-15265 have an EU (EUVD) identifier?

Yes. CVE-2025-15265 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2733.

When was CVE-2025-15265 published?

CVE-2025-15265 was published on 2026-01-15 and last updated on 2026-06-17.

CVE-2025-15265

CVE-2025-15265 is a medium-severity vulnerability in Svelte with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 5.3
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2733
Weakness: CWE-79
Affected product: Svelte
Published: 2026-01-15
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-15265?: 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.
How severe is CVE-2025-15265?: CVE-2025-15265 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-15265 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-15265?: CVE-2025-15265 affects Svelte. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-15265?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-15265 have an EU (EUVD) identifier?: Yes. CVE-2025-15265 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2733.
When was CVE-2025-15265 published?: CVE-2025-15265 was published on 2026-01-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*

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