# Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level Advisory record · `GHSA-qfwc-vx6f-3g6g` - **Identifiers:** `GHSA-qfwc-vx6f-3g6g` · `CVE-2026-91985` · `GO-2026-6747` - **State:** Confirmed - **Severity:** CVSS 8.7 High - **Critical:** No - **Weakness (CWE):** [CWE-200](https://cwe.mitre.org/data/definitions/200.html) · [CWE-639](https://cwe.mitre.org/data/definitions/639.html) · [CWE-862](https://cwe.mitre.org/data/definitions/862.html) - **Tags:** [Information disclosure](https://agentprime.io/advisories/tag/info-disclosure.md) · [Broken access control](https://agentprime.io/advisories/tag/access-control.md) - **Published:** 9 Oct 2026 - **Updated:** 19 Oct 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 9 Oct 2026, 20:51 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `code.vikunja.io/api` (Go): affected `<2.6.0`; fixed in `2.6.0` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > GHSA-qfwc-vx6f-3g6g affects the Go module code.vikunja.io/api versions before 2.6.0. A user with read-only access to a project can call the single link-share read endpoint (v1 and v2) and receive the share's hash, which can be exchanged for a link-share token carrying the share's permission level, allowing writes the user is not entitled to. Upgrade to version 2.6.0 or later. The source lists no other workaround. Written 1 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 8.7 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`, from CNA (VulnCheck) - **CISA KEV:** Not listed. - **EPSS:** 0.0043, the 37th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:11 UTC: First seen by agentprime - 31 Oct 2026, 14:11 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-qfwc-vx6f-3g6g) ## Sources - [GitHub Advisory Database: GHSA-qfwc-vx6f-3g6g](https://github.com/advisories/GHSA-qfwc-vx6f-3g6g) - [OSV: GHSA-qfwc-vx6f-3g6g](https://osv.dev/vulnerability/GHSA-qfwc-vx6f-3g6g) - - - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .