CVE-2021-40531: Sketch before 75 allows library feeds to be used to bypass file quarantine

Q: How do I fix CVE-2021-40531?

sketch: upgrade to 75. Exact commands for each OS are on this page.

Q: Is CVE-2021-40531 being exploited?

CVE-2021-40531 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-2021-40531 affect?

CVE-2021-40531 affects sketch. Severity is critical (CVSS 9.8). Sketch before 75 allows library feeds to be used to bypass file quarantine. Files are automatically downloaded and opened, without the com.apple.quarantine extended attribute. This results in remote code execution, as demonstrated by Comman

Q: How urgent is CVE-2021-40531?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-40531 is a critical-severity flaw (CVSS 9.8) affecting sketch. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sketch before 75 allows library feeds to be used to bypass file quarantine. Files are automatically downloaded and opened, without the com.apple.quarantine extended attribute. This results in remote code execution, as demonstrated by CommandString in a terminal profile to Terminal.app.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
Public exploit reference
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	33.0% (top 2%)
CISA exploited list	No
Weakness	CWE-434
Published	2021-09-06
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: sketch

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

Am I affected?

Timeline

2021-09-06 21:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

sketch sketch UPGRADE

Affected: < 75

Fixed in: 75

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy sketch || rpm -q sketch || sketch --version

2. UPGRADE to 75 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sketch

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sketch

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-2021-40531?

sketch: upgrade to 75. Exact commands for each OS are on this page.

Is CVE-2021-40531 being exploited?

CVE-2021-40531 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-2021-40531 affect?

CVE-2021-40531 affects sketch. Severity is critical (CVSS 9.8). Sketch before 75 allows library feeds to be used to bypass file quarantine. Files are automatically downloaded and opened, without the com.apple.quarantine extended attribute. This results in remote code execution, as demonstrated by Comman

How urgent is CVE-2021-40531?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

References

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