devalue: Custom ArrayBuffer revivers can bypass typed-array allocation validation
GHSA-r9w8-h9r3-54w4 · published 1 Oct 2026
How serious is it
- Severity: high, CVSS score 8.2 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by GHSA-r9w8-h9r3-54w4?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
devalue(npm) <= 5.9.2
How to check
- Run
npm ls devaluein your project to see the installed version, including copies pulled in by other packages. - Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
- Or run
npx shippable-dev scan localhost:3000in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.
How to fix
Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
- Upgrade
devalueto 5.9.3 or later, commit the lockfile and redeploy. - If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
Under very specific circumstances, `parse` could create massive ArrayBuffers with very small input. This required a malformed `ArrayBuffer` custom reviver.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- github.com/sveltejs/devalue/security/advisories/GHSA-r9w8-h9r3-54w4
- github.com/sveltejs/devalue/commit/8f8d78e173f8a00023d009c7677ccc600dee0b99
- github.com/sveltejs/devalue/releases/tag/v5.9.3
- github.com/advisories/GHSA-r9w8-h9r3-54w4
Merged from GitHub Advisory Database. Last updated 23 Oct 2026. All vulnerabilities · RSS · JSON