Information Disclosure Vulnerability in Letta by Letta AI
CVE-2026-77938

7.1HIGH

Key Information:

Vendor

Letta-ai

Status
Letta
Vendor
CVE Published:
20 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-77938?

Letta versions up to 0.16.8 contain an information disclosure flaw where the LocalSandbox subprocesses have access to the full server environment. This allows malicious users executing tools via POST requests to read sensitive server secrets, including LETTA_PG_URI, POSTGRES_PASSWORD, and provider API keys. Consequently, this vulnerability can lead to unauthorized access to cross-tenant database information, posing a significant risk to data integrity and confidentiality.

Affected Version(s)

letta 0 <= 0.16.8

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-77938 - Proof of Concept

References

https://www.lasso.security/vulnerability-database/cve-202...
technical-descriptionexploit
https://github.com/letta-ai/letta/blob/1131535716e8a31c9a...
technical-description
https://www.vulncheck.com/advisories/letta-through-0.16.8...
third-party-advisory

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Noy Pearl
Michael Sromin
Ophir Dror
.