CVE-2026-57957
Papermark through 0.22.0 contains a cross-origin resource sharing (CORS) misconfiguration vulnerability that allows unauthenticated remote a
CVSS
4.7
Medio
EPSS
0.4%
p35
KEV
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Exploit Today
11
0-100
Publicado: 29 jun 2026 · Última mod.: 14 jul 2026 · CWE-942
0.4%EPSS · 30 días0.4%
2026-08-272026-09-25
Papermark through 0.22.0 contains a cross-origin resource sharing (CORS) misconfiguration vulnerability that allows unauthenticated remote attackers to perform credentialed cross-origin requests by exploiting the TUS-based viewer upload endpoint reflecting arbitrary request Origins with Access-Control-Allow-Credentials set to true. Attackers can lure authenticated victims to malicious pages that silently issue credentialed cross-origin requests to upload arbitrary files into victim datarooms and read credentialed responses.
CVECVSSEPSSKEVRExplotTítuloVis.
CVE-2026-66070—33.0%
——10RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6, match_origin/1 returned the bare reflected Origin and allowed credentials even when the wildcard "" was configured, so the response echoed the attacker's origin together with Access-Control-Allow-Credentials. The affected code is rabbit_mgmt_cors.erl. When the management plugin is configured with a wildcard CORS origin (cors_allow_origins = ""), the handler reflects the request Origin back in Access-Control-Allow-Origin and also sends Access-Control-Allow-Credentials: true. A malicious web page that a signed-in administrator visits can then use that administrator's cached HTTP Basic credentials to issue authenticated, state-changing requests to the management API. Preconditions include The management plugin is configured with the wildcard cors_allow_origins = "*", which is an explicit operator misconfiguration A target administrator has a cached HTTP Basic-auth session in the browser. This issue is fixed in versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6.1dCVE-2026-90882—35.7%
——11The open-vsx.org deployment returned Access-Control-Allow-Origin reflecting the requesting origin together with Access-Control-Allow-Credentials: true on the authenticated /user/ endpoints. A page on any origin could therefore issue credentialed requests to the service in a logged-in user's browser and read the responses.
This exposed /user (login name, avatar, homepage, tokens URL), /user/tokens, /user/namespaces, /user/extensions, /user/search/{name} and /user/namespace/{name}/members, and — because /user/csrf was readable the same way — allowed the CSRF protection on write endpoints to be defeated. Chaining the two, an attacker page could call /user/token/create and exfiltrate a personal access token carrying publish and delete rights over the victim's namespaces.
The headers were emitted by the CDN/edge layer, not by the application: the Open VSX software sets allowCredentials(true) in exactly one place, against a single exact origin derived from ovsx.webui.url, and defines no CORS mapping on /user/ beyond it. No configuration of the software produces origin reflection with credentials.3dCVE-2026-565953.1 BAJ13.2%
——4HCL BigFix Service Management is affected by a CORS Misconfiguration vulnerability due to improperly validated origin headers, which could allow an attacker to craft a malicious web page that interacts with the vulnerable application, enabling unauthorized access to protected resources and restricted APIs on behalf of a victim.7dCVE-2026-890587.4 ALT38.5%
——12A flaw was found in RESTEasy's CorsFilter, which, when configured to allow all origins ("*"), reflects the request's Origin header back in the Access-Control-Allow-Origin response together with Access-Control-Allow-Credentials: true. This permissive cross-origin policy allows a malicious website to make credentialed cross-origin requests and read authenticated responses from a victim's session, resulting in a loss of confidentiality.6dCVE-2026-923593.1 BAJ17.7%
——5A security flaw has been discovered in ag-ui-protocol ag-ui 0.3.0. The affected element is the function create_strands_app of the file integrations/aws-strands/python/src/ag_ui_strands/utils.py of the component CORSMiddleware. The manipulation results in permissive cross-domain policy with untrusted domains. The attack may be launched remotely. The attack requires a high level of complexity. The exploitability is described as difficult. Upgrading to version AGUI.Abstractions@0.0.6 is sufficient to fix this issue. The patch is identified as 9b143b9668fa52c2054ede9d34a45ac4b4401089. It is suggested to upgrade the affected component.2dCVE-2026-824388.1 ALT10.1%
——3Description
Three separate mechanisms allowed a web page on an unrelated origin to read responses that Storm's HTTP
components served to an authenticated user.
The Logviewer reflected the request's `Origin` header back in `Access-Control-Allow-Origin` while also
sending `Access-Control-Allow-Credentials: true`. The published security model documents a permissive
`Access-Control-Allow-Origin: *` posture as accepted, which is safe precisely because browsers refuse to
honour `*` together with credentials; reflecting the concrete origin removes that protection.
The shared CORS filter used by the UI, the Logviewer and DRPC was configured with a response header name
where an initialisation parameter name was expected. The container ignored the setting and applied its own
defaults, which allow credentials.
Finally, the UI and Logviewer wrapped API responses in a caller-supplied JSONP callback for every GET
request. A script element on any origin can load such a response, which bypasses the same-origin policy
entirely rather than negotiating it, and there was no way to turn the behaviour off.
In each case the effect is that a page visited by an authenticated operator can read cluster, topology and
log data on their behalf.
Mitigation
Upgrade to 3.1.0, where the Logviewer no longer reflects the request origin in a credentialed response, the
CORS filter is configured explicitly, and JSONP wrapping is governed by `ui.enable.jsonp`, which defaults to
false.
Note that disabling JSONP is a behaviour change for tooling that passes a `callback` query parameter; such
tooling should be moved to ordinary JSON requests.
Users who cannot upgrade immediately should place the UI, Logviewer and DRPC HTTP endpoints behind a reverse
proxy that strips `Access-Control-Allow-Origin` and `Access-Control-Allow-Credentials` from responses and
rejects requests carrying a `callback` parameter.
Credit
The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.11d