# CVE-2026-121819: CVE-2026-121819

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

A vulnerability has been identified in armeria-xds versions 1.40.0 through 1.42.0, where DataSourcePolicy checks filename containment without resolving symbolic links, allowing a compromised or semi-trusted xDS control plane to cause the xDS client to read files outside configured allowed root directories when a symbolic link inside an allowed directory points outside it. In deployments using a credential injector, header-compatible text secrets may be exposed to an attacker-observable upstream.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- LY Corporation / Armeria: ≥ 1.40; < 1.43.0 (affected, custom). Source: CNA: LY-Corporation

## Severity and prioritization

- CVSS 4.0: 5.9 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: LY-Corporation

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-59

## Exploit evidence

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

## References

- https://line.github.io/security-advisory-blog/CVE-2026-121819/ (CNA: LY-Corporation)

- https://github.com/line/armeria/security/advisories/GHSA-m64h-m6r5-6jrx (CNA: LY-Corporation)

## Provenance

- CNA: LY-Corporation: https://www.cve.org/CVERecord?id=CVE-2026-121819; retrieved 2026-11-06; source updated 2026-11-06

Revision: 64755585c6aaae79106568a4370f780241ef32ccf76125e3bf6976c135e9115e

Canonical: https://y2.dev/cve/CVE-2026-121819

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