high8.1
CVE-2026-77937
Letta through 0.16.8 contains an authentication bypass vulnerability that allows API callers to impersonate other users by supplying a self-asserted user_id HT…
Impact
Letta through 0.16.8 contains an authentication bypass vulnerability that allows API callers to impersonate other users by supplying a self-asserted user_id HTTP header. Attackers can set user_id to another tenant's ID, even with LETTA_SERVER_SECURE enabled, to read and modify that user's agents, memory and configuration.
Affected products
| Product | Affected versions |
|---|---|
| Letta | through 0.16.8 |
Versions were read from the advisory text. No structured product data has been published for this record yet.
Weakness classification
References
- NVD record
- CVE.org record
- https://github.com/letta-ai/letta/blob/1131535716e8a31c9a437f8695e25ac98f203a24/letta/server/rest_api/dependencies.py#L39
- https://www.lasso.security/vulnerability-database/cve-2026-77937
- https://www.vulncheck.com/advisories/letta-through-0.16.8-cross-tenant-impersonation-via-user-id-header