# CVE-2026-121548: nnn through 5.3 OS Command Injection via togglex Plugin

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

Jarun nnn through 5.3 contains an OS command injection vulnerability in plugins/togglex that allows attackers to execute commands via crafted filenames. Attackers can place files whose names contain a double quote and shell syntax, which xargs -I splices into an sh -c script, running commands as the user invoking togglex.

## 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://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff

## Affected products and versions

- jarun / nnn: ≥ 0; ≤ 5.3 (affected, custom). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.4 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: VulnCheck

- CVSS 4.0: 8.4 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/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: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

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

- Weaknesses: CWE-78

## Exploit evidence

- exploit: https://github.com/jarun/nnn/issues/2188 (ADP: CISA-ADP)

## References

- https://github.com/jarun/nnn/issues/2188 (CNA: VulnCheck; issue-tracking)

- https://github.com/jarun/nnn (CNA: VulnCheck; product)

- https://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff (CNA: VulnCheck; patch)

- https://github.com/jarun/nnn/blob/v5.3/plugins/togglex#L15 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/nnn-through-5.3-os-command-injection-via-togglex-plugin (CNA: VulnCheck; third-party-advisory)

- https://github.com/jarun/nnn/issues/2188 (ADP: CISA-ADP; exploit)

- https://github.com/jarun/nnn (disclosure@vulncheck.com)

- https://github.com/jarun/nnn/blob/v5.3/plugins/togglex#L15 (disclosure@vulncheck.com)

- https://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff (disclosure@vulncheck.com)

- https://github.com/jarun/nnn/issues/2188 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/nnn-through-5.3-os-command-injection-via-togglex-plugin (disclosure@vulncheck.com)

- https://github.com/jarun/nnn/issues/2188 (134c704f-9b21-4f2e-91b3-4a467353bcc0)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121548; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121548; retrieved 2026-11-03; source updated 2026-11-03

Revision: ce58a462c9a3909ba733397bd54697f48748c32eb2ee3e88f84ba5bbca8ddeae

Canonical: https://y2.dev/cve/CVE-2026-121548

## 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.

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