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TI-2021-21541 Aliases CVE-2021-46872GHSA-6fm4-9v93-v7gg

An issue was discovered in Nim before 1.6.2.

Priority LOW 28CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-79.

Summary

An issue was discovered in Nim before 1.6.2. The RST module of the Nim language stdlib, as used in NimForum and other products, permits the javascript: URI scheme and thus can lead to XSS in some applications. (Nim versions 1.6.2 and later are fixed; there may be backports of the fix to some earlier versions. NimForum 2.2.0 is fixed.)

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00562 46th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:*before 1.6.2Vulnerablenim-lang
cpe:2.3:a:nim-lang:nimforum:*:*:*:*:*:nim:*:*before 2.2.0Vulnerablenim-lang
  • cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:* Versions before 1.6.2 Vulnerable ·nim-lang
  • cpe:2.3:a:nim-lang:nimforum:*:*:*:*:*:nim:*:* Versions before 2.2.0 Vulnerable ·nim-lang

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-46872
  2. 2026-10-03 Alias added: GHSA-6fm4-9v93-v7gg

References

Patch 2

Advisory 3

  • TI-2020-12364 In Nim 1.2.4, the standard library browsers mishandles the URL argument to… CVSS 3.1CRITICAL 9.8
  • TI-2020-12363 In Nim before 1.2.6, the standard library asyncftpclient lacks a check for whether a… CVSS 3.1CRITICAL 9.8
  • TI-2021-04471 Nimble arbitrary code execution for specially crafted package metadata CVSS 3.1HIGH 8.8
  • TI-2021-04473 Nimble fails to validate certificates due to insecure httpClient defaults CVSS 3.1HIGH 8.1
  • TI-2020-12366 In Nim 1.2.4, the standard library httpClient fails to properly validate the server… CVSS 3.1HIGH 7.5
  • TI-2021-04472 Nimble falls back to insecure http url when fetching packages CVSS 3.1HIGH 7.5
See all 8 →

Sources

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