CVE-2026-54290Published

Hono: CORS Middleware reflects any Origin with credentials when `origin` defaults to the wildcard

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-54290

Published

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, with credentials: true and no explicit origin (the default wildcard), the CORS Middleware reflects the request's Origin and sends Access-Control-Allow-Credentials: true. Any site can then make credentialed cross-origin requests and read the responses, exposing cookie-authenticated endpoints to arbitrary origins. This vulnerability is fixed in 4.12.25.

Source published: 22 Jun 2026 17:15:35 UTC
Source modified: 22 Jun 2026 17:26:12 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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CVSS 3.1 · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

euvd · EUVD-2026-38329

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Jun 22, 2026, 5:15:35 PM

dateUpdated: Jun 22, 2026, 5:26:12 PM

Source published: Jun 22, 2026, 5:15:35 PM (timezone not stated)
Source modified: Jun 22, 2026, 5:26:12 PM (timezone not stated)
Observed here: 7 Nov 2026 12:29:11 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

nvd · CVE-2026-54290

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-942

Original publisher date fields

published: 2026-06-22T18:16:47.620

lastModified: 2026-10-25T23:10:00.167

Source published: 22 Jun 2026 18:16:47 UTC
Source modified: 25 Oct 2026 23:10:00 UTC
Observed here: 27 Oct 2026 14:13:32 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

osv · GHSA-88fw-hqm2-52qc

Published

### Summary With `credentials: true` and no explicit `origin` (the default wildcard), the CORS Middleware reflects the request's `Origin` and sends `Access-Control-Allow-Credentials: true`. Any site can then make credentialed cross-origin requests and read the responses, exposing cookie-authenticated endpoints to arbitrary origins. ### Details The spec forbids `Access-Control-Allow-Origin: *` with credentials and browsers reject it, so this configuration used to fail closed. In affected versions the middleware reflects the request `Origin` instead, so it now succeeds for every origin, including `null`. The preflight also echoes the requested headers back, approving non-simple credentialed requests too. This issue arises when an application enables `credentials: true` and leaves `origin` unset or set to the wildcard. ### Impact Any third-party page a logged-in user visits can read the application's cookie-authenticated endpoints and perform credentialed state-changing requests. This affects applications that enable credentialed CORS without restricting `origin`.

Source published: 16 Jun 2026 14:15:39 UTC
Source modified: 10 Sep 2026 03:50:48 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

Publisher rating · HIGH