How severe is CVE-2026-34041?

CVE-2026-34041 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-2026-34041 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34041?

CVE-2026-34041 affects Nektos Act. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34041?

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.

Does CVE-2026-34041 have an EU (EUVD) identifier?

Yes. CVE-2026-34041 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17287.

When was CVE-2026-34041 published?

CVE-2026-34041 was published on 2026-03-31 and last updated on 2026-06-17.

CVE-2026-34041

CVE-2026-34041 is a critical-severity vulnerability in Nektos Act 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. The underlying weakness is classified as CWE-74.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 7.7
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17287
Weakness: CWE-74
Affected product: Nektos Act
Published: 2026-03-31
Last modified: 2026-06-17

Description

act is a project which allows for local running of github actions. Prior to version 0.2.86, act unconditionally processes the deprecated ::set-env:: and ::add-path:: workflow commands, which was disabled due to environment injection risks. When a workflow step echoes untrusted data to stdout, an attacker can inject these commands to set arbitrary environment variables or modify the PATH for all subsequent steps in the job. This issue has been patched in version 0.2.86.

Frequently asked questions

What is CVE-2026-34041?: act is a project which allows for local running of github actions. Prior to version 0.2.86, act unconditionally processes the deprecated ::set-env:: and ::add-path:: workflow commands, which was disabled due to environment injection risks. When a workflow step echoes untrusted data to stdout, an attacker can inject these commands to set arbitrary environment variables or modify the PATH for all subsequent steps in the job. This issue has been patched in version 0.2.86.
How severe is CVE-2026-34041?: CVE-2026-34041 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-2026-34041 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34041?: CVE-2026-34041 affects Nektos Act. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34041?: 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.
Does CVE-2026-34041 have an EU (EUVD) identifier?: Yes. CVE-2026-34041 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17287.
When was CVE-2026-34041 published?: CVE-2026-34041 was published on 2026-03-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nektos:act:*:*:*:*:*:*:*:*

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