Security readout for executives and security teams
Plain-English summary
Heym before 0.0.21 lets an authenticated user influence where uploaded files are stored. A crafted filename can escape the intended upload directory, potentially allowing files to be written, read, or deleted elsewhere on the server.
Executive priority
Treat this as a high-priority remediation for any internet-facing or multi-user Heym deployment. The main business risk is unauthorized modification of server files through legitimate authenticated access.
Technical view
The issue is a CWE-22 path traversal flaw in the upload_file() handler. The CVE states that filename input was not sufficiently validated, allowing traversal sequences to bypass path restrictions. Impact is CVSS 7.6: low confidentiality, high integrity, and low availability impact.
Likely exposure
Exposure is most likely in deployments running Heym before 0.0.21 where authenticated users, tenants, or integrations can access the file upload endpoint. Public internet exposure increases urgency, but authentication is required according to the CVE bundle.
Exploitation context
The source bundle does not indicate CISA KEV listing or confirmed active exploitation. Exploitation requires authenticated access and a crafted filename, so insider, compromised-account, or multi-tenant abuse scenarios are the main concern.
Researcher notes
Evidence supports Heym before 0.0.21, CWE-22, CVSS 7.6, and a patch-associated commit. The exact affected package boundaries beyond the provided version and commit are not fully detailed in the bundle, so confirm with upstream metadata.
Mitigation direction
- Upgrade Heym to version 0.0.21 or later.
- Apply the upstream patch if direct version upgrade is not immediately possible.
- Restrict upload access to trusted users until remediation is complete.
- Review vendor release notes and advisory for any additional guidance.
Validation and detection
- Inventory Heym deployments and confirm installed versions.
- Verify upload endpoints are not reachable by untrusted authenticated users.
- Review upload and application logs for suspicious filename patterns.
- Check server directories for unexpected files outside upload storage.
- Confirm the deployed code includes the referenced upstream fix.
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-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-45225 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
- High
- CVSS
- 7.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
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
2 official scoresWe 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:L/UI:N/S:U/C:L/I:H/A:L2.84.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
7.2HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.6HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
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/heymrun/heym/releases/tag/v0.0.21CVE reference, VulnCheck · release-notes
- https://github.com/heymrun/heym/pull/92CVE reference, VulnCheck · issue-tracking
- https://github.com/heymrun/heym/commit/835843e6d2bf7d018cbb8e50f28f0426eaa20c84CVE reference, VulnCheck · patch
- https://www.vulncheck.com/advisories/heym-path-traversal-file-upload-via-upload-fileCVE reference, VulnCheck · third-party-advisory
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.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.