CVE-2021-23543
Sandbox Bypass
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Sandbox Bypass
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
- Record
CVE-2021-23543- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P - Updated
- 2026-11-02
EUVDEUVD-2022-0670
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
- Record
EUVD-2022-0670- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-q4j7-v27r-fgcx
Prototype Pollution in realms-shim
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
- Record
GHSA-q4j7-v27r-fgcx- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
NVD
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
- Record
CVE-2021-23543- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSVGHSA-q4j7-v27r-fgcx
Prototype Pollution in realms-shim
All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.
- Record
GHSA-q4j7-v27r-fgcx- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
realms-shimnpm |
through 1.2.2 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-23543 is a critical vulnerability (CVSS 9.8) in Agoric Realms-shim, published January 7, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.82%, the 78th percentile. No source names a fixed version.