Security readout for executives and security teams
Plain-English summary
This flaw can make a website trust the wrong origin for browser cross-origin requests. If an application uses elysia-cors through 1.3.0 and expects only exact trusted domains, a lookalike origin could be accepted because the library checks for substrings.
Executive priority
Treat this as a moderate application security issue. Prioritize internet-facing services that use elysia-cors for sensitive browser data flows, but do not treat it as confirmed exploited based on the supplied evidence.
Technical view
The issue is an origin validation error in elysia-cors through 1.3.0. The supplied origin is accepted when it appears as a substring of a configured allowed domain, instead of requiring an exact origin match. The supplied CVSS is 6.5 medium with network access, low complexity, and user interaction required.
Likely exposure
Exposure is likely limited to applications using elysia-cors through 1.3.0 for CORS allowlist enforcement, especially where trusted domains are configured and sensitive browser-accessible routes rely on that control.
Exploitation context
The bundle does not show KEV listing or confirmed active exploitation. The CVSS vector indicates remote exploitation with low complexity but requires user interaction. Public references include a write-up and a GitHub commit, so awareness is public.
Researcher notes
The source bundle names elysia-cors through 1.3.0, but affected CPE/product fields are n/a. There is also tension between the description's user-data impact and the supplied CVSS vector showing confidentiality none and integrity high.
Mitigation direction
- Identify applications using elysia-cors through version 1.3.0.
- Review vendor guidance and the referenced GitHub commit for the exact fix.
- Upgrade to a fixed package version when confirmed by the project.
- Require exact origin matching for configured CORS allowlists.
- Avoid broad or substring-based domain allow rules for sensitive routes.
Validation and detection
- Inspect dependency manifests and lockfiles for elysia-cors versions.
- Review CORS configuration for exact trusted origins only.
- Test that lookalike origins are rejected by protected endpoints.
- Confirm deployed code includes the vendor's origin-matching correction.
- Check logs for unusual cross-origin requests to sensitive routes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-178: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-50864 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N2.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/elysiajs/elysia-cors/blob/main/src/index.tsCVE reference, mitre
- https://github.com/elysiajs/elysia-cors/tree/mainCVE reference, mitre
- https://medium.com/@raghavagrawal_23036/cors-bypass-in-popular-opensource-library-ad27fb41e16aCVE reference, mitre
- https://github.com/elysiajs/elysia-cors/commit/9b9eb92e32a7a4b43b6d5108668941701c33e221CVE reference, mitre
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.