Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Banks versions before 2.5.0 are vulnerable. Prompt.chat_messages() parses each rendered output line as a chat message JSON object, so user-controlled template input that renders as JSON with a role such as system can be returned as a privileged message. An attacker who can supply input to an application that renders untrusted text with this method and passes the results directly to an LLM provider could inject system, assistant, or tool messages and override intended instructions. Upgrade to Banks 2.5.0 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 6.5 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0034, the 27th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:08 UTC First seen by agentprime
- 31 Oct 2026, 14:08 UTC Confirmed by OSV