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TI-2025-34871 Aliases CVE-2025-55195

@std/toml Prototype Pollution in Node.js and Browser

Priority HIGH 71CWE-1321Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

@std/toml is the Deno Standard Library. Prior to version 1.0.9, an attacker can pollute the prototype chain in Node.js runtime and Browser when parsing untrusted TOML data, thus achieving Prototype Pollution (PP) vulnerability. This is because the library is merging an untrusted object with an empty object, which by default the empty object has the prototype chain. This issue has been patched in version 1.0.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00364 30th percentileScored 2026-11-07
Fix Fixed std (denoland): 1.0.9

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
denolandstdbefore 1.0.91.0.9Patch availableCNA
  • std Vendordenoland Affected before 1.0.9 Fixed in 1.0.9 Patch available CNA

Remediation

  • Fix · CNA std (denoland) Fixed in 1.0.9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-55195

References

Other 3

  • TI-2026-21627 Deno has a Command Injection via Incomplete shell metacharacter blocklist in node:child_process CVSS 3.1CRITICAL 9.8
  • TI-2025-17782 Deno's AES GCM authentication tags are not verified CVSS 4.0HIGH 7.7
  • TI-2024-18537 *const c_void / ExternalPointer unsoundness leading to use-after-free CVSS 3.1HIGH 8.8
  • TI-2024-18536 Deno arbitrary file descriptor close via `op_node_ipc_pipe()` leading to permission prompt bypass CVSS 3.1HIGH 8.8
  • TI-2023-12990 Deno is vulnerable to interactive `run` permission prompt spoofing via improper ANSI neutralization CVSS 3.1HIGH 8.8
  • TI-2023-11328 Regular expression denial of service in deno CVSS 3.1HIGH 7.5
See all 43 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences