How severe is CVE-2021-30502?

CVE-2021-30502 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-30502 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30502?

CVE-2021-30502 affects Simple Glasgow Haskell Compiler Project Simple Glasgow Haskell Compiler. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-30502?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-30502 published?

CVE-2021-30502 was published on 2021-04-25 and last updated on 2026-06-17.

CVE-2021-30502

CVE-2021-30502 is a critical-severity vulnerability in Simple Glasgow Haskell Compiler Project Simple Glasgow Haskell Compiler with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Simple Glasgow Haskell Compiler Project Simple Glasgow Haskell Compiler
Published: 2021-04-25
Last modified: 2026-06-17

Description

The unofficial vscode-ghc-simple (aka Simple Glasgow Haskell Compiler) extension before 0.2.3 for Visual Studio Code allows remote code execution via a crafted workspace configuration with replCommand.

Frequently asked questions

What is CVE-2021-30502?: The unofficial vscode-ghc-simple (aka Simple Glasgow Haskell Compiler) extension before 0.2.3 for Visual Studio Code allows remote code execution via a crafted workspace configuration with replCommand.
How severe is CVE-2021-30502?: CVE-2021-30502 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-30502 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30502?: CVE-2021-30502 affects Simple Glasgow Haskell Compiler Project Simple Glasgow Haskell Compiler. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-30502?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-30502 published?: CVE-2021-30502 was published on 2021-04-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:simple_glasgow_haskell_compiler_project:simple_glasgow_haskell_compiler:*:*:*:*:*:visual_studio_code:*:*