# CVE-2026-123040: CVE-2026-123040

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

An attacker who gains the ability to execute arbitrary code on a system with TrueConf Server (Linux) versions from 4.7.2 up to, but not including, 5.5.6 installed, running as the user trueconf (by exploiting some other vulnerability), can elevate their privileges to root.

## Remediation

- fix: Update TrueConf Server (Linux) to versions 5.5.6 or newer. (source: CNA: Kaspersky)
- workaround: Perform a full check with anti-virus software that has up-to-date anti-virus databases and software modules. (source: CNA: Kaspersky)

## Affected products and versions

- TrueConf / TrueConf Server: ≥ 4.7.2; < 5.5.6 (affected, semver). Source: CNA: Kaspersky; platforms: Linux

## Severity and prioritization

- CVSS 4.0: 8.5 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: Kaspersky

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

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-276

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://ics-cert.kaspersky.com/advisories/2026/11/10/trueconf-server-linux-incorrect-default-permissions/ (CNA: Kaspersky; third-party-advisory)

## Provenance

- CNA: Kaspersky: https://www.cve.org/CVERecord?id=CVE-2026-123040; retrieved 2026-11-11; source updated 2026-11-11

Revision: b7f762bc5c0142c5c78a749ad625932430c75090856e51a3af89fa32be5c319c

Canonical: https://y2.dev/cve/CVE-2026-123040

## 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.