42/100 CVSS 7.4 🔴 CVE ANALYSISPublished: July 6, 2026

Coder's AI Bridge Proxy skips TLS certificate verification in default configuration

### Summary The AI Bridge Proxy (`aibridgeproxyd`) created a goproxy server whose default transport set `InsecureSkipVerify: true` and only assigned a secure transport when an upstream proxy was configured. In the default configuration (no upstream proxy), outbound HTTPS to the Coder access URL accepted any TLS certificate. > **Note:** Practical ex...

7.4

CVSS Score

LOW

Threat Level

Priority /100

TBD

Exploited ITW

Monitor

CISA Status

Sources

🔵

HIGH-PRIORITY SECURITY ADVISORY — Priority Score: 42/100

CVSS 7.4 LOW. SENTINEL APEX recommends immediate patch evaluation. Intelligence from 1 confirmed source(s).

📋 Executive Summary

⚡ Analyst Assessment — SENTINEL APEX v4.0

This report analyzes CVE-2026-55436 affecting go github.com/coder/coder/v2 (CVSS 7.4, LOW severity). No confirmed in-the-wild exploitation at the time of writing; prioritize on exposure, privilege, and CVSS. Corroborated across 1 source(s): github_advisories. Verify all specifics against the primary sources linked below before acting.

Intelligence sources: github_advisories

🧮 Severity Anatomy — CVSS 3.1 vector, decoded from the primary record

The base score summarizes severity in one number; the vector explains why. Each row below is a direct read of the official CVSS vector — verifiable against the NVD record.

Metric	Value	What it means for defenders
Attack Vector	Network `AV:N`	Remotely exploitable across the network — internet-facing instances are directly at risk.
Attack Complexity	High `AC:H`	Depends on conditions outside attacker control (race, specific config) — harder to weaponize.
Privileges Required	None `PR:N`	No authentication needed — pre-auth exploitation.
User Interaction	None `UI:N`	No victim action required — fully automatable.
Scope	Unchanged `S:U`	Impact confined to the vulnerable component.
Confidentiality Impact	High `C:H`	Total loss of confidentiality — full data disclosure possible.
Integrity Impact	High `I:H`	Total loss of integrity — attacker can modify any data.
Availability Impact	None `A:N`	No availability impact.

🧬 Weakness Anatomy — CWE-295, the underlying flaw class

This vulnerability is classified as CWE-295: Improper Certificate Validation in the primary record. The mechanics below are characteristic of this weakness class (per the MITRE CWE corpus), not a claim about a specific exploit observed against your environment.

How it's exploited	Attacker with network position exploits weak TLS validation to intercept or spoof connections (MITM).
Detect & prevent	Enforce full chain + hostname validation; pin where feasible. Detect via TLS-anomaly and unexpected CA monitoring.

⚠️ Business Impact Analysis

⚠️ Remote code execution — full server takeover without authentication possible

🔗 Representative Attack Path

A typical attack path for this vulnerability class, mapped to MITRE ATT&CK. This is a representative model to guide detection and defense — not a claim of observed activity against a specific target. Confirm specifics against the primary sources below.

#	Phase	Attacker Action	MITRE
1	Reconnaissance	Attacker identifies exposed github.com/coder/coder/v2 instances via Shodan, Censys, or targeted scanning	`TA0043`
2	Initial Access	Exploitation of CVE-2026-55436 in go github.com/coder/coder/v2	`T1190`
3	Execution	Remote code execution achieved — attacker runs arbitrary commands on target system	`T1203`
4	Persistence	Backdoor, scheduled task, or new admin account created for persistent access	`T1053`
5	Command & Control	Attacker establishes persistent C2 channel using HTTPS or DNS tunneling	`T1071`
6	Impact / Objectives	Intellectual property theft, espionage, cryptomining, or preparation for future attack stage	`T1657`

⚠ Deep Dive Analysis

This high-severity vulnerability in go github.com/coder/coder/v2 (CVSS 7.4) represents a significant attack surface. SENTINEL APEX assesses exploitation to be technically feasible with moderate effort. Organizations running github.com/coder/coder/v2 in internet-facing or privileged positions face immediate risk.

SENTINEL APEX URGENCY: ELEVATED. Score: 42/100 LOW. Patch before exploitation activity begins.

🧠 Structured Intelligence Assessment

SENTINEL APEX analytical tradecraft separates verified fact from labeled assessment and states intelligence gaps explicitly. Confidence reflects evidentiary support, not certainty.

✔ Verified Facts

Affected CVE(s): CVE-2026-55436, CVE-2026-55436.
Affected technology: go github.com/coder/coder/v2.
CVSS base score of 7.4 assigned by an authoritative source.
1 MITRE ATT&CK technique(s) evidenced in the source material.

🕸️ Correlated Observations

Vendor go has been targeted in 7 prior CYBERDUDEBIVASH reports (recurring target)
Product github.com/coder/coder/v2 has been targeted in 7 prior CYBERDUDEBIVASH reports (recurring target)
Related prior intelligence: cve-2026-55428-go-github-com-coder-coder-v2 (2 shared entities), cve-2026-55075-go-github-com-coder-coder-v2 (2 shared entities), cve-2026-55076-go-github-com-coder-coder-v2 (2 shared entities), cve-2026-55077-go-github-com-coder-coder-v2 (2 shared entities), cve-2026-55431-go-github-com-coder-coder-v2 (2 shared entities)

🧩 Analyst Assessments

MEDIUM CONF Technical severity is assessed as high (CVSS 7.4); realized business impact depends on asset exposure and data classification.

❓ Intelligence Gaps

No confirmed public IOCs are available at report time; detection currently relies on behavioral analytics.
In-the-wild exploitation is unconfirmed as of this report.
Attribution to a specific threat actor is not established by the available evidence.

🔮 Forward Outlook

MEDIUM CONF Given the repeated targeting pattern, further activity against this vendor/sector is probable.

🧬 Prior Intelligence Context

This report is correlated against CYBERDUDEBIVASH SENTINEL APEX's persistent analyst memory. The following entities have been tracked in prior intelligence:

Vendor go — previously observed 7 times in CYBERDUDEBIVASH intelligence since 2026-07-06 (recent: cve-2026-55077-go-github-com-coder-coder-v2, cve-2026-55431-go-github-com-coder-coder-v2)
Product github.com/coder/coder/v2 — previously observed 7 times in CYBERDUDEBIVASH intelligence since 2026-07-06 (recent: cve-2026-55077-go-github-com-coder-coder-v2, cve-2026-55431-go-github-com-coder-coder-v2)
ATT&CK technique T1557 — previously observed once in CYBERDUDEBIVASH intelligence since 2026-07-06 (recent: cve-2026-55427-go-github-com-coder-coder-v2)

🎯 MITRE ATT&CK Mapping

Category	Mapping
Primary Tactic	ML Attack Staging
Primary Technique	AML.T0040 — ML Attack Staging
Sub-Technique	AML.T0000 — AI/ML System Enumeration
Weakness (CWE)	CWE-295
Intel Type	🔴 CVE ANALYSIS
Source(s)	github_advisories

🔴 CVE Reference

CVE ID	Reference	Score
CVE-2026-55436	NVD →	7.4
CVE-2026-55436	NVD →	7.4

🔍 Detection Rules — Sigma (SIEM)

Deploy to Splunk, Elastic, Microsoft Sentinel, or QRadar. SOC Pro subscribers receive pre-compiled SIEM-native query packs updated with each pipeline run.

Sigma YAMLtitle: CVE-2026-55436 Exploitation Attempt — go github.com/coder/coder/v2
id: 0d25355475ba5ef9-1ab0
status: experimental
description: Detects exploitation of CVE-2026-55436 in go github.com/coder/coder/v2. Priority: LOW. Score: 42/100
author: CYBERDUDEBIVASH SENTINEL APEX v4.0 (bivash@cyberdudebivash.com)
date: 2026-07-06
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-55436
    - https://blog.cyberdudebivash.in/
tags:
    - attack.initial_access
    - attack.t1190
    - cve-2026-55436
    - cve-2026-55436
logsource:
    category: webserver
detection:
    keywords:
        - 'CVE-2026-55436'
        - 'CVE-2026-55436'
        - 'cve-2026-55436'
    condition: keywords
falsepositives:
    - Security scanners
level: medium

📡 Detection Rules — YARA (Endpoint)

Deploy to endpoint detection platforms. Enterprise subscribers receive tuned, FP-validated YARA rule packs.

YARArule CVE_2026_55436_Exploitation {
    meta:
        description = "Detects artifacts related to CVE-2026-55436 exploitation in go github.com/coder/coder/v2"
        author      = "CYBERDUDEBIVASH SENTINEL APEX v4.0"
        date        = "2026-07-06"
        severity    = "HIGH"
        cvss        = "7.4"
        priority    = "42/100"
        threat_level = "LOW"
        reference   = "https://nvd.nist.gov/vuln/detail/CVE-2026-55436"
    strings:
        $id_str  = "CVE-2026-55436" ascii nocase
        $product = "github_com_coder_coder_v2" ascii nocase wide
    condition:
        any of them
}

🎯 Multi-Audience Intelligence Products

This single analysis is packaged for every stakeholder — from the boardroom to the SOC — plus a machine-readable feed for API and MSSP integration. Enterprise & SOC Pro subscribers receive these as structured deliverables.

🏛 Executive Advisory — CISO / Security Leadership

Affected CVE(s): CVE-2026-55436, CVE-2026-55436.
Affected technology: go github.com/coder/coder/v2.
CVSS base score of 7.4 assigned by an authoritative source.
1 MITRE ATT&CK technique(s) evidenced in the source material.

Owner	Decision	Timeline
CISO / SOC Lead	Authorize response activation and detection deployment	Within 24h
Vulnerability Mgmt	Prioritize remediation/patching of go assets	Within 7 days
Legal / Privacy	Assess regulatory notification obligations if in-scope data is at risk	Within 48h

📋 Board Brief

A high-severity cyber threat affects go github.com/coder/coder/v2.
Technical severity is rated 7.4/10.
Primary exposure is operational disruption, data loss, and potential regulatory liability (e.g. GDPR, NIS2, DORA, SOC 2) where in-scope systems are affected.
Mitigation depends on vendor guidance and compensating controls.
Recommended posture: authorize prioritized remediation and confirm detection coverage with the security team.

🛡 SOC Bulletin

Severity HIGH · Detection coverage: 0 technique(s) across behavioral analytics · 0 network rule(s)

P1: Sweep 14 days of telemetry for the mapped ATT&CK techniques.
P2: Update threat-intel platform and downstream detection feeds with confirmed indicators.

🔭 Threat Hunting Guide

T1557 — Adversary-in-the-Middle: Hunt for adversary-in-the-middle activity (credential-access); evidence basis: te:** Practical exploitation requires an on-path (man-in-the-middle) position between the AI Bridge Proxy and the Cod

⎋ Machine-readable intelligence: this report is available as a structured JSON package (MITRE ATT&CK, IOCs, multi-platform detections, analyst assessments) at /api/intel/products/cve-2026-55436-go-github-com-coder-coder-v2.json — built for SIEM, SOAR, and MSSP integration.

🛡️ SOC Response Playbook

1IMMEDIATE (0-1hr): Identify all instances of github.com/coder/coder/v2 in your environment via CMDB/asset inventory
2IMMEDIATE (0-1hr): Apply vendor patch — no maintenance window exception for LOW threats
3IMMEDIATE (1-2hr): If no patch available: implement WAF rules, ACLs, or network-level compensating controls
4SHORT-TERM (2-4hr): Deploy Sigma detection rule to SIEM — validate alert generation in test environment
5SHORT-TERM (4-8hr): Review logs for exploitation indicators (anomalous github.com/coder/coder/v2 requests, error spikes)
6SHORT-TERM (8-24hr): Hunt for post-exploitation: new admin accounts, scheduled tasks, lateral movement
7MONITOR: Subscribe to go security advisories for patch updates
8ONGOING: Track SENTINEL APEX intelligence feed for follow-on campaigns targeting github.com/coder/coder/v2

📎 Intelligence References

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⚡ CYBERDUDEBIVASH SENTINEL APEX v4.0

Intelligence report generated by CYBERDUDEBIVASH SENTINEL APEX v4.0
Report ID: SENTINEL-CVE-2026-55436-2026-07-06 | Priority: 42/100 LOW | Sources: 1
© 2026 CYBERDUDEBIVASH PRIVATE LIMITED
Republication requires written attribution to CYBERDUDEBIVASH SENTINEL APEX

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