CVE-2026-47676 json
Hono: app.mount() strips mount prefix using undecoded path, causing incorrect routing for percent-encoded paths
published 5mo ago modified 28d ago also EUVD-2026-32924 , GHSA-2gcr-mfcq-wcc3
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 17%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm hono 4.12.21
- hono hono 4.12.21
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | hono | <4.12.21 |
4.12.21 |
Affected products
- honojs hono
Classification
References
-
github.com
/honojs/hono/commit/6cbb025ff87fca1a3d00d0ccca0eaf3a6385c3f1
web
-
github.com
/honojs/hono/security/advisories/GHSA-2gcr-mfcq-wcc3
web, vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-47676
advisory
-
github.com
/honojs/hono
package
-
github.com
/honojs/hono/releases/tag/v4.12.21
web
Sources
- CVE List CVE-2026-47676
- GitHub Advisory GHSA-2gcr-mfcq-wcc3
- NVD CVE-2026-47676
- Maintainer advisory GHSA-2gcr-mfcq-wcc3
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of honojs/hono published their own advisory on GitHub. Reviewed sources take precedence over it.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.