Security readout for executives and security teams
Plain-English summary
Decidim sites in the affected version ranges can let a remote attacker run JavaScript in a logged-in user's browser through the processes filter. The business risk is account-context action abuse, including causing users to endorse or support proposals they did not intend to support.
Executive priority
Treat as high priority for public civic engagement platforms because it can undermine user trust and integrity of participation outcomes, even without evidence of active exploitation.
Technical view
CVE-2023-34089 is a CWE-79 cross-site scripting issue in Decidim's processes filter. It affects Decidim versions >= 0.14.0 and < 0.26.7, and >= 0.27.0 and < 0.27.3. CVSS 3.1 is 8.1 with network access, low attack complexity, no privileges, and required user interaction.
Likely exposure
Exposure is likely for internet-facing Decidim deployments running the affected versions, especially public participation portals with authenticated users and active proposal workflows.
Exploitation context
The supplied sources do not show active exploitation, and the CVE is not listed as KEV. Exploitation requires user interaction and runs JavaScript in the context of a logged-in user.
Researcher notes
The key evidence is the Decidim advisory, CVE record, affected version ranges, and CVSS vector. Do not assume broader Decidim components are affected unless vendor sources confirm it.
Mitigation direction
- Upgrade Decidim to 0.26.7, 0.27.3, or a later fixed release.
- Review the GitHub advisory and release notes for vendor-specific guidance.
- Prioritize public Decidim portals with active participation or proposal endorsement workflows.
- Monitor for unexpected endorsements, supports, or user reports of unwanted actions.
Validation and detection
- Inventory all Decidim instances and record their deployed versions.
- Compare versions against >= 0.14.0, < 0.26.7 and >= 0.27.0, < 0.27.3.
- Confirm production is running 0.26.7, 0.27.3, or later.
- Review recent proposal endorsement/support activity for unusual user-disputed actions.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2023-34089 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
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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.
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:H/I:H/A:N2.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/decidim/decidim/security/advisories/GHSA-5652-92r9-3fx9CVE reference · x_refsource_CONFIRM
- https://github.com/decidim/decidim/releases/tag/v0.26.6CVE reference · x_refsource_MISC
- https://github.com/decidim/decidim/releases/tag/v0.27.3CVE reference · x_refsource_MISC
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 Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.