CVE-2021-30502: The unofficial vscode-ghc-simple (aka Simple Glasgow Haskell Compiler) extension before 0.2.3 for Visual Studi

Q: How do I fix CVE-2021-30502?

simple glasgow haskell compiler: upgrade to 0.2.3. Exact commands for each OS are on this page.

Q: Is CVE-2021-30502 being exploited?

CVE-2021-30502 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-30502 affect?

CVE-2021-30502 affects simple glasgow haskell compiler. Severity is critical (CVSS 9.8). 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.

Q: How urgent is CVE-2021-30502?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-30502 is a critical-severity flaw (CVSS 9.8) affecting simple glasgow haskell compiler. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.9% (top 13%)
CISA exploited list	No
Published	2021-04-25
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: simple glasgow haskell compiler project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-04-25 03:15 UTCPublished CVE record published
2026-06-17 03:50 UTCUpdated Record last modified

simple glasgow haskell compiler project simple glasgow haskell compiler UPGRADE

Affected: < 0.2.3

Fixed in: 0.2.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy simple-glasgow-haskell-compiler || rpm -q simple-glasgow-haskell-compiler || simple-glasgow-haskell-compiler --version

2. UPGRADE to 0.2.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade simple-glasgow-haskell-compiler

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade simple-glasgow-haskell-compiler

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-30502?

simple glasgow haskell compiler: upgrade to 0.2.3. Exact commands for each OS are on this page.

Is CVE-2021-30502 being exploited?

CVE-2021-30502 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-30502 affect?

CVE-2021-30502 affects simple glasgow haskell compiler. Severity is critical (CVSS 9.8). 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 urgent is CVE-2021-30502?

Priority 61/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Visual Studio vulnerabilities

References

← Back to latest CVEs