How severe is CVE-2026-21697?

CVE-2026-21697 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-21697 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21697?

CVE-2026-21697 affects Rezmoss Axios4go. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21697?

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

Does CVE-2026-21697 have an EU (EUVD) identifier?

Yes. CVE-2026-21697 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1381.

When was CVE-2026-21697 published?

CVE-2026-21697 was published on 2026-01-07 and last updated on 2026-06-17.

CVE-2026-21697

CVE-2026-21697 is a high-severity vulnerability in Rezmoss Axios4go with a CVSS 3.x base score of 8.1. 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-362.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v4: 8.2
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1381
Weakness: CWE-362
Affected product: Rezmoss Axios4go
Published: 2026-01-07
Last modified: 2026-06-17

Description

axios4go is a Go HTTP client library. Prior to version 0.6.4, a race condition vulnerability exists in the shared HTTP client configuration. The global `defaultClient` is mutated during request execution without synchronization, directly modifying the shared `http.Client`'s `Transport`, `Timeout`, and `CheckRedirect` properties. Impacted applications include that that use axios4go with concurrent requests (multiple goroutines, `GetAsync`, `PostAsync`, etc.), those where different requests use different proxy configurations, and those that handle sensitive data (authentication credentials, tokens, API keys). Version 0.6.4 fixes this issue.

Frequently asked questions

What is CVE-2026-21697?: axios4go is a Go HTTP client library. Prior to version 0.6.4, a race condition vulnerability exists in the shared HTTP client configuration. The global `defaultClient` is mutated during request execution without synchronization, directly modifying the shared `http.Client`'s `Transport`, `Timeout`, and `CheckRedirect` properties. Impacted applications include that that use axios4go with concurrent requests (multiple goroutines, `GetAsync`, `PostAsync`, etc.), those where different requests use different proxy configurations, and those that handle sensitive data (authentication credentials, tokens, API keys). Version 0.6.4 fixes this issue.
How severe is CVE-2026-21697?: CVE-2026-21697 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-21697 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21697?: CVE-2026-21697 affects Rezmoss Axios4go. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21697?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-21697 have an EU (EUVD) identifier?: Yes. CVE-2026-21697 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1381.
When was CVE-2026-21697 published?: CVE-2026-21697 was published on 2026-01-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:rezmoss:axios4go:*:*:*:*:*:go:*:*

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