Security readout for executives and security teams
Plain-English summary
CVE-2026-1126 is an unrestricted file upload issue in lwj flow’s SVG file handling. A remote, authenticated user may be able to upload files that should not be allowed, creating risk to confidentiality, integrity, and availability. Public exploit information is reported, but the sources do not show confirmed active exploitation.
Executive priority
Treat as a moderate priority if lwj flow is internet-facing or broadly accessible to users. Prioritize validation and access restriction because public exploit information exists and no confirmed vendor fix is cited in the provided sources.
Technical view
The issue affects FormResource.java uploadFile in flow-front-rest, specifically the SVG File Handler. The File argument can be manipulated, leading to unrestricted upload. VulDB maps it to CWE-434 and CWE-284. The CVSS v2 score is 6.5 with network access, low complexity, and single authentication required.
Likely exposure
Exposure is likely limited to organizations running lwj flow at or before commit a3d2fe8133db9d3b50fda4f66f68634640344641, especially where the flow front REST service and SVG upload functionality are reachable by users. Rolling release versioning prevents clear affected-version boundaries.
Exploitation context
The advisory states the attack can be carried out remotely and that exploit details have been publicly disclosed. CVSS indicates authentication is required. CISA KEV is not indicated, and the provided sources do not confirm in-the-wild exploitation.
Researcher notes
Evidence is based mainly on VulDB, CVE records, and the linked Gitee issue. The project reportedly has not responded, and rolling release delivery means fixed and affected versions are unclear. Avoid assuming unauthenticated access or active exploitation without new evidence.
Mitigation direction
- Check the project issue and repository for vendor response or corrected code.
- Restrict access to upload functionality to trusted users only.
- Limit exposure of the flow front REST service to trusted networks.
- Apply strict file type, content, and storage controls if supported.
- Monitor uploads and application logs for suspicious file activity.
Validation and detection
- Identify whether lwj flow is deployed in your environment.
- Confirm the deployed commit or code lineage against the affected commit.
- Review FormResource.java uploadFile handling for unrestricted file acceptance.
- Verify whether SVG upload endpoints are reachable by authenticated users.
- Check logs for unusual upload activity or unexpected stored files.
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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupCWE-434: 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 lookupCVE-2026-1126 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 (2.0)
- Known Exploited
- No
- Published
Vector: AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
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.
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.
AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR86.4Primary CVE scoreVulnerability scoring details
Base CVSS 2.0 score
6.5MediumVector: AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
Source materials
- CVE List V5 sourceCVE List V5
- VDB-341718 | lwj flow SVG File FormResource.java uploadFile unrestricted uploadCVE reference · vdb-entry, technical-description
- VDB-341718 | CTI Indicators (IOB, IOC, TTP, IOA)CVE reference · signature, permissions-required
- Submit #735122 | https://gitee.com/lwj/flow flowable 1.0 Arbitrary File UploadCVE reference · third-party-advisory
- https://gitee.com/lwj/flow/issues/IDIQSECVE reference · exploit, issue-tracking
- https://gitee.com/lwj/flow/CVE reference · product
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 Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.