Critical severity · published Oct 20, 2026
CVE-2026-77936
Letta through 0.16.8 Insecure Default Configuration Unauthenticated API and PostgreSQL Access
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
Letta through 0.16.8 ships a compose.yaml that does not enable LETTA_SERVER_SECURE, so the password middleware is never added and all API routes are unauthenticated, and it exposes a superuser PostgreSQL port with default credentials. Remote attackers can execute arbitrary Python via POST /v1/tools/run, manage /v1/admin users, or run OS commands via COPY PROGRAM.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LE
letta · letta-ai
through 0.16.8 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77936
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77936
github.com
https://github.com/letta-ai/letta/blob/1131535716e8a31c9a437f8695e25ac98f203a24/compose.yaml#L17
github.com
https://github.com/letta-ai/letta/blob/1131535716e8a31c9a437f8695e25ac98f203a24/letta/server/rest_api/app.py#L799
www.lasso.security
https://www.lasso.security/vulnerability-database/cve-2026-77936
www.vulncheck.com
https://www.vulncheck.com/advisories/letta-through-0.16.8-insecure-default-configuration-unauthenticated-api-and-postgresql-access
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