Medium severity6.5NVD Advisory· Published Oct 20, 2026

CVE-2026-77938

Description

Letta through 0.16.8 contains an information disclosure vulnerability that allows users running tools to read server secrets because LocalSandbox subprocesses inherit the full server environment. Attackers can run code via POST /v1/tools/run or custom tools to read LETTA_PG_URI, POSTGRES_PASSWORD, and provider API keys, then access cross-tenant database data.

Affected products

Letta/Lettallm-fuzzy
Range: <=0.16.8

Patches

Vulnerability mechanics

References

github.com/letta-ai/letta/blob/1131535716e8a31c9a437f8695e25ac98f203a24/letta/services/tool_sandbox/base.pynvd
www.lasso.security/vulnerability-database/cve-2026-77938nvd
www.vulncheck.com/advisories/letta-through-0.16.8-credential-exposure-via-tool-sandbox-environment-inheritancenvd

News mentions

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epss	0.000
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