MediumVulnerabilityLLM-specific

CVE-2026-126767: OpsTree REMS prompt injection exposes hidden system prompt via /api/v1/rca/chat

Source: NVD(opens in a new tab)
Identifier: CVE-2026-126767
Published: November 11, 2026
Record updated: November 12, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.3%

Summary

OpsTree REMS through 1.0.0 contains a prompt injection vulnerability, tracked as CVE-2026-126767. Authenticated users can send crafted chat input to POST /api/v1/rca/chat to make the assistant ignore its rules and disclose its hidden system prompt, including internal orchestration instructions. That disclosure can help an attacker craft further prompt injection attacks.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Details

Scores and exploitation

CVSS score: 4.3(medium)
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector: network
Attack complexity: low
Privileges required: low
User interaction: none
EPSS: 0.3%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 12, 2026.
Disclosure date: November 11, 2026

Weaknesses and techniques

AI threat technique (MITRE ATLAS): AML.T0051

Classification

Attack type: Prompt injection
Attack sophistication: Trivial
AI component targeted: API
Impact: Confidentiality,
Integrity
Labels: security,
safety

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-126767

First tracked: November 11, 2026 at 07:10 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Topics

Prompt injection and jailbreaks

Summary

Mitigation

Topics

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