How severe is CVE-2026-42420?

CVE-2026-42420 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-42420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42420?

CVE-2026-42420 affects Openclaw. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42420?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-42420 have an EU (EUVD) identifier?

Yes. CVE-2026-42420 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26123.

When was CVE-2026-42420 published?

CVE-2026-42420 was published on 2026-04-28 and last updated on 2026-06-17.

CVE-2026-42420

CVE-2026-42420 is a medium-severity vulnerability in Openclaw with a CVSS 3.x base score of 4.3. 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-770.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26123
Weakness: CWE-770
Affected product: Openclaw
Published: 2026-04-28
Last modified: 2026-06-17

Description

OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.

Frequently asked questions

What is CVE-2026-42420?: OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.
How severe is CVE-2026-42420?: CVE-2026-42420 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-42420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42420?: CVE-2026-42420 affects Openclaw. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42420 have an EU (EUVD) identifier?: Yes. CVE-2026-42420 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26123.
When was CVE-2026-42420 published?: CVE-2026-42420 was published on 2026-04-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*

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