StackPrism

npm package

svelte 3.50.1 vulnerabilities, and the version that fixes all of them

svelte 3.50.1 has 8 known vulnerabilities (1 rated high or critical); 5.55.7 fixes all of them. Svelte 3 reached end of life on Jun 22, 2023 and gets no more security fixes. Move to Svelte 5.

npm (opens in a new tab) describes it as “Cybernetically enhanced web apps”

Known vulnerabilities
8
1 rated high or critical
Released
Sep 8, 2022
Latest is 5.57.2
Downloads last week
2.8K
Under 1% of svelte downloads
Svelte 3 support
End of life
Since Jun 22, 2023
Licence
MIT
OpenSSF Scorecard
7.6/10
sveltejs/svelte (opens in a new tab)
Dependencies
None
Resolved by deps.dev

What to upgrade to

5.55.7 is the closest release with no known vulnerabilities.

  • 3.59.2

    Newest 3.x release. Released Jun 20, 2023.

    7 known vulnerabilities, worst rated warning

  • 5.55.7Upgrade to this

    Fixes all 8 known vulnerabilities. Released May 14, 2026.

    No known vulnerabilities

  • 5.57.2

    Latest release. Released Oct 6, 2026.

    No known vulnerabilities

5.55.7 came out on May 14, 2026. A coding agent trained before then doesn’t know it exists, so it may suggest an older release. AI knowledge cutoff dates

Hand the fix to your coding agent

One task with the upgrade, the file to change and why. Paste it into Claude Code, Cursor or Codex.

Findings

Every advisory for svelte 3.50.1

Known exploited first (CISA KEV), then by how likely they are to be exploited (FIRST EPSS), then by severity. Each id links to its OSV.dev record.

  1. WarningCVE-2026-27125 on OSV.dev (opens in a new tab)GHSA-crpf-4hrx-3jrpEPSS: top 58%

    Svelte SSR attribute spreading includes inherited properties from prototype chain

    Fixed in 5.51.5. Published Feb 19, 2026.

  2. WarningCVE-2026-27901 on OSV.dev (opens in a new tab)GHSA-phwv-c562-gvmhEPSS: top 68%

    Svelte vulnerable to XSS during SSR with contenteditable `bind:innerText` and `bind:textContent`

    Fixed in 5.53.5. Published Feb 26, 2026.

  3. WarningCVE-2024-45047 on OSV.dev (opens in a new tab)GHSA-8266-84wp-wv5cEPSS: top 72%

    Svelte has a potential mXSS vulnerability due to improper HTML escaping

    Fixed in 4.2.19. Published Aug 30, 2024.

  4. WarningCVE-2026-42573 on OSV.dev (opens in a new tab)GHSA-rcqx-6q8c-2c42EPSS: top 74%

    Svelte Vulnerable to XSS via DOM Clobbering of Internal Framework State

    Fixed in 5.55.7. Published May 14, 2026.

  5. WarningCVE-2026-42599 on OSV.dev (opens in a new tab)GHSA-pr6f-5x2q-rwfpEPSS: top 87%

    Svelte SSR vulnerable to cross-site scripting via spread attributes

    Fixed in 5.55.7. Published May 14, 2026.

  6. WarningCVE-2026-27122 on OSV.dev (opens in a new tab)GHSA-m56q-vw4c-c2cpEPSS: top 88%

    Svelte SSR does not validate dynamic element tag names in `<svelte:element>`

    Fixed in 5.51.5. Published Feb 19, 2026.

  7. WarningCVE-2026-27121 on OSV.dev (opens in a new tab)GHSA-f7gr-6p89-r883EPSS: top 88%

    Svelte affected by cross-site scripting via spread attributes in Svelte SSR

    Fixed in 5.51.5. Published Feb 19, 2026.

  8. CriticalGHSA-gw32-9rmw-qwww on OSV.dev (opens in a new tab)

    svelte is vulnerable to XSS with textarea bind:value

    Fixed in 3.59.2. Published Jan 16, 2026.

Who is still on a vulnerable svelte

40% of last week’s 6.8M svelte downloads went to versions with known vulnerabilities.

From npm’s per-version download counts for the last 7 days, each version checked against OSV.dev. The versions checked cover over 99% of downloads.

Is svelte the only one?

Paste a public GitHub repo or drop your package.json and see every vulnerable, end-of-life or deprecated dependency, with one fix task. Free, no sign-up.

Check your whole repo

How this page is checked

StackPrism asks OSV.dev which advisories affect exactly svelte 3.50.1, merges duplicates filed under several ids, and ranks them with CISA’s Known Exploited Vulnerabilities list and FIRST EPSS. Release dates and deprecation come from deps.dev and npm, support dates from endoflife.date. No AI writes this page: every sentence comes from that data, refreshed every few hours.

Last checked against npm, OSV.dev, deps.dev, CISA KEV, FIRST EPSS and endoflife.date.