How severe is CVE-2026-47676?

CVE-2026-47676 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-47676 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-47676?

CVE-2026-47676 affects Hono. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-47676?

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

Does CVE-2026-47676 have an EU (EUVD) identifier?

Yes. CVE-2026-47676 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32924.

When was CVE-2026-47676 published?

CVE-2026-47676 was published on 2026-05-28 and last updated on 2026-06-17.

CVE-2026-47676

CVE-2026-47676 is a medium-severity vulnerability in Hono with a CVSS 3.x base score of 5.3. 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-444.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32924
Weakness: CWE-444
Affected product: Hono
Published: 2026-05-28
Last modified: 2026-06-17

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed against the percent-decoded path. This inconsistency causes the prefix to be stripped at the wrong position when the path contains percent-encoded multi-byte characters, resulting in the mounted sub-application receiving an incorrect path. This vulnerability is fixed in 4.12.21.

Frequently asked questions

What is CVE-2026-47676?: Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed against the percent-decoded path. This inconsistency causes the prefix to be stripped at the wrong position when the path contains percent-encoded multi-byte characters, resulting in the mounted sub-application receiving an incorrect path. This vulnerability is fixed in 4.12.21.
How severe is CVE-2026-47676?: CVE-2026-47676 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-47676 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-47676?: CVE-2026-47676 affects Hono. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-47676?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-47676 have an EU (EUVD) identifier?: Yes. CVE-2026-47676 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32924.
When was CVE-2026-47676 published?: CVE-2026-47676 was published on 2026-05-28 and last updated on 2026-06-17.

References

https://github.com/honojs/hono/security/advisories/GHSA-2gcr-mfcq-wcc3

Affected products (1)

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

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