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No exploitation reported

CVE-2021-23543

No exploitation reported by the sources we read.

  • Published2022-01-10
  • WeaknessCWE-1321

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.

Timeline

dates in UTC
  1. 2022-01-1014:10CVE publishedNVD

Versions per branch

OSV · NVD
realms-shim
BranchAffectedFixed in
1.2≤ 1.2.2no fix published
Agoric realms-shim
BranchAffectedFixed in
—all versionsno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 3.19.8known since 2026-10-23
  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-1321read 2026-10-23
  • FIRST EPSSEPSS score1.8 %2026-11-09
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryCRITICAL2022-01-11

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2022-01-10
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-q4j7-v27r-fgcx

Frequently asked questions

What is CVE-2021-23543?

All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.

Is CVE-2021-23543 actively exploited?

Active exploitation of CVE-2021-23543 has not been confirmed. Its EPSS score was 1.8% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-23543?

CVE-2021-23543 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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