# CVE-2026-123524: Vikunja 0.23.0 before 2.7.1 Information Disclosure via Webhook related_tasks Payload

Status: published. Published: 2026-11-08. Updated: 2026-11-12.

Vikunja from 0.23.0 before 2.7.1 contains an information disclosure vulnerability that allows project collaborators with write access to read tasks from inaccessible projects by registering webhooks. Because webhook payloads are built with the triggering user's permissions, attackers receive related_tasks titles, descriptions and metadata from private projects whenever another user modifies a linked task.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- go-vikunja / vikunja (code.vikunja.io/api): ≥ 0.23.0; < 2.7.1 (affected, semver); 2.7.1 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.9 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 5.7 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N; source: CNA: VulnCheck

- CVSS 4.0: 6.9 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 5.7 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.31% as of 2026-11-10; percentile 24.36%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-863

## Exploit evidence

- exploit: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-66cq-j6rw-pjch (ADP: CISA-ADP)

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-66cq-j6rw-pjch (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/vikunja-0.23.0-before-2.7.1-information-disclosure-via-webhook-related-tasks-payload (CNA: VulnCheck; third-party-advisory)

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-66cq-j6rw-pjch (ADP: CISA-ADP; exploit)

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-66cq-j6rw-pjch (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/vikunja-0.23.0-before-2.7.1-information-disclosure-via-webhook-related-tasks-payload (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-123524; retrieved 2026-11-12; source updated 2026-11-12

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123524; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-123524; retrieved 2026-11-11; source updated Not reported

Revision: 6270e9ca11258def70009be3c4f41afe9159d9f6421396f7803099f6dc70ae7f

Canonical: https://y2.dev/cve/CVE-2026-123524

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.