# CVE-2026-121728: SourceHut meta.sr.ht 0.56.11 before 0.89.0 Registration Authorization Bypass via /register/step2

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

SourceHut meta.sr.ht 0.56.11 before 0.89.0 contains an authorization bypass vulnerability that allows unauthenticated attackers to register accounts when public registration is disabled. Attackers can obtain a CSRF token from /login and POST credentials to /register/step2, which invokes the unchecked GraphQL RegisterAccount mutation to create accounts.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://git.sr.ht/~sircmpwn/meta.sr.ht/commit/e471ffe75bb6ef11366e46c3b721dd0278f746b5

## Affected products and versions

- SourceHut / meta.sr.ht: ≥ 0.56.11; < 0.89.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

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

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: VulnCheck

- CVSS 4.0: 6.9 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-862

## Exploit evidence

- exploit: https://blog.arusekk.pl/posts/srht-disabled-registration-bypass/ (CNA: VulnCheck)

## References

- https://git.sr.ht/~sircmpwn/meta.sr.ht/commit/e471ffe75bb6ef11366e46c3b721dd0278f746b5 (CNA: VulnCheck; patch)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/commit/1ea24685a76f6456245d0bc7fe6accf6231c4044 (CNA: VulnCheck; technical-description)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/tree/0.88.9/item/metasrht/blueprints/auth.py#L121 (CNA: VulnCheck; technical-description)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/refs/0.89.0 (CNA: VulnCheck; release-notes)

- https://blog.arusekk.pl/posts/srht-disabled-registration-bypass/ (CNA: VulnCheck; technical-description, exploit)

- https://www.vulncheck.com/advisories/sourcehut-meta-sr-ht-0.56.11-before-0.89.0-registration-authorization-bypass-via-register-step2 (CNA: VulnCheck; third-party-advisory)

- https://blog.arusekk.pl/posts/srht-disabled-registration-bypass/ (disclosure@vulncheck.com)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/commit/1ea24685a76f6456245d0bc7fe6accf6231c4044 (disclosure@vulncheck.com)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/commit/e471ffe75bb6ef11366e46c3b721dd0278f746b5 (disclosure@vulncheck.com)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/refs/0.89.0 (disclosure@vulncheck.com)

- https://git.sr.ht/~sircmpwn/meta.sr.ht/tree/0.88.9/item/metasrht/blueprints/auth.py#L121 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/sourcehut-meta-sr-ht-0.56.11-before-0.89.0-registration-authorization-bypass-via-register-step2 (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121728; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121728; retrieved 2026-11-04; source updated 2026-11-03

Revision: cac0ae8305fc8611ee3bee129f670f2c8b3cf0998a29dde7a3441b387dff5e59

Canonical: https://y2.dev/cve/CVE-2026-121728

## 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.