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Vulnerability · Published Oct 8, 2025 · Assigned by GitHub_M

CVE-2025-61785Deno's --deny-write check does not prevent permission bypass

Low 3.3

In plain English

A low-severity security flaw in deno from denoland. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 3.0)3.3Low
Exploit odds (30 days)0.2%top 89.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Deno is a JavaScript, TypeScript, and WebAssembly runtime. In versions prior to 2.5.3 and 2.2.15, `Deno.FsFile.prototype.utime` and `Deno.FsFile.prototype.utimeSync` are not limited by the permission model check `--deny-write=./`. It's possible to change to change the access (`atime`) and modification (`mtime`) times on the file stream resource even when the file is opened with `read` only permission (and `write`: `false`) and file write operations are not allowed (the script is executed with `--deny-write=./`). Similar APIs like `Deno.utime` and `Deno.utimeSync` require `allow-write` permission, however, when a file is opened, even with read only flags and deny-write permission, it's still possible to change the access (`atime`) and modification (`mtime`) times, and thus bypass the permission model. Versions 2.5.3 and 2.2.15 fix the issue.

Affected products (as reported)

VendorProductVersions
denoland deno >= 2.3.0, < 2.5.3< 2.2.15

Weakness: CWE-266 · Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References