MediumVulnerabilityLLM-specific

CVE-2026-123851: JetBrains Junie GitHub Action prompt injection bypass via HTML encoding

Source: NVD(opens in a new tab)
Identifier: CVE-2026-123851
Published: November 6, 2026
Record updated: November 6, 2026

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

Summary

CVE-2026-123851 affects the JetBrains Junie GitHub Action before version 1.6.4. Its prompt injection protection could be bypassed using HTML-encoded characters.

Mitigation

Fixed in 1.6.4.

Details

Scores and exploitation

CVSS score: 5.4(medium)
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Attack vector: network
Attack complexity: low
Privileges required: none
User interaction: required
EPSS: Not scored. FIRST had not published an EPSS score for this CVE when it was last checked on November 6, 2026.
Disclosure date: November 6, 2026

Weaknesses and techniques

Weakness (CWE): CWE-180
AI threat technique (MITRE ATLAS): AML.T0051
AML.T0054

Classification

Attack type: Prompt injection,
Jailbreak
Attack sophistication: Trivial
AI component targeted: Agent
Impact: Integrity,
Safety
Labels: security

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-2026-123851

First tracked: November 6, 2026 at 01:10 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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