SSRF in Letta
CVE-2026-4964
A security vulnerability has been detected in letta-ai letta 0.16.4. This vulnerability affects the function _convert_message_create_to_message of the file letta/helpers/message_helper.py of the component File URL Handler. Such manipulation of the argument ImageContent leads to server-side request forgery. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (30.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Letta — versions 0.16.4
- Letta-Ai Letta — versions 0.16.4
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (Exploit, VDB Entry, Third Party Advisory, third-party-advisory)
- gist.github.com/YLChen-007/fde4d5ed6ac4aa876f73f8954c6214da (Exploit, Third Party Advisory, exploit)
Frequently asked questions
- What is CVE-2026-4964?
- CVE-2026-4964 is a medium-severity vulnerability in Letta, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.3/10. Published 2026-03-27.
- How severe is CVE-2026-4964?
- Medium severity. CVSS v3 base score is 6.3 out of 10.