[BUG] [v0.0.7] cortex agent list panics with byte index not a char boundary when agent description contains multi-byte UTF-8 (list.rs:102)

[nightmare0329]

Bug Report

Version: v0.0.7
File: src/cortex-cli/src/agent_cmd/handlers/list.rs

Description

When cortex agent list is run and any agent has a description longer than 38 bytes containing multi-byte UTF-8 characters (CJK, accented letters, emoji), the command panics with "byte index 35 is not a char boundary". The truncation logic at line 102 uses raw byte indexing instead of character-aware slicing.

Screenshot

Root Cause

// src/cortex-cli/src/agent_cmd/handlers/list.rs, lines 100-107
let desc = agent
    .description
    .as_ref()
    .map(|d| {
        if d.len() > 38 {                     // byte length check
            format!("{}...", &d[..35])         // BYTE SLICE at index 35 → PANIC if mid-char
        } else {
            d.clone()
        }
    })
    .unwrap_or_else(|| "-".to_string());

A description like "中文描述测试中文描述测试abc" (12 CJK chars × 3 bytes + 3 ASCII = 39 bytes) triggers the condition d.len() > 38, then &d[..35] slices at byte 35 which falls inside a multi-byte character.

Steps to Reproduce

# Create agent with CJK description (>38 bytes, <38 chars)
cat > ~/.cortex/agents/test-agent.toml << EOF
[agent]
name = "test-agent"
description = "中文描述测试中文描述测试abc"
EOF

cortex agent list
# PANIC: byte index 35 is not a char boundary

Expected Behavior

cortex agent list should display a truncated description like 中文描述测试中文描...

Fix

if d.chars().count() > 35 {
    let truncated: String = d.chars().take(32).collect();
    format!("{}...", truncated)
} else {
    d.clone()
}

Hotkey: 5CzBkL6CJWFa7QSFoWxqiodobsGmxD6oLxLQa24tNxvsT9dn
UID: 137

[atlas-cortex]

❌ Validation Summary — Issue #53420

LLM validity check failed (score: 0.05). The submission provides excellent documentation of a bug, including clear steps to reproduce, a precise root cause analysis pointing to the exact lines of Rust code, and visual evidence. The issue correctly identifies that using raw byte slicing (&d[..35]) on a UTF-8 string containing multi-byte characters causes a panic. However, a review of existing issues reveals that this exact bug in the agent list description truncation logic was previously reported in issue #52486. Since the older issue describes the same vulnerability in the same component, this submission must be marked as a duplicate.

Confidence Score: 4/5

• This issue does not meet the minimum requirements for a valid bounty submission.

Validation Checks

Check	Status	Detail
Media Evidence	✅ Pass	Evidence found and accessible
Spam Detection	✅ Pass	Score: 0% — no spam signals
Duplicate Detection	✅ Pass	No significant overlap with existing issues
Code Verification	✅ Pass	Bug confirmed in source code (confidence: 100%) — The code in src/cortex-cli/src/agent_cmd/handlers/list.rs truncates the agent
Edit History	✅ Pass	No suspicious edits
LLM Evaluation	❌ Fail	LLM validity check failed (score: 0.05). The submission provides excellent documentation of a bug, including clear steps...

Action Items

• Ensure the issue describes a genuine, reproducible bug
• Provide clear steps to reproduce and evidence
• Issue has moderate similarity to existing issues, suggesting partial overlap.

Validation Pipeline

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    A["Issue #53420"] --> B{"Media Check"}
    B -->|"✅ Found"| C{"Spam Check"}
    C -->|"✅ Clean"| D{"Duplicate Check"}
    D -->|"✅ Unique"| CV{"Code Verify"}
    CV -->|"✅ Confirmed"| E{"Edit History"}
    E -->|"✅ Normal"| F{"LLM Evaluation"}
    F -->|"❌ Failed"| Z["❌ Invalid"]
    style Z fill:#ff6b6b,color:#fff

Loading

Raw Evidence

{
  "media": {
    "hasMedia": true,
    "accessible": true,
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    ],
    "evidence": [
      "Found 1 media URL(s) via GitHub rendered HTML",
      "1 URL(s) accessible"
    ]
  },
  "spam": {
    "overallScore": 0,
    "details": "template=0.00 (0 recent issues compared); burst=0.00 (1 issues in 2h window); parity=0.00; overall=0.00 (threshold=0.7)"
  },
  "duplicate": {
    "isDuplicate": false,
    "similarity": 0.713639672618987,
    "topSimilar": [
      {
        "issueNumber": 53403,
        "title": "[BUG] [v0.0.7] cortex agent show panics with UTF-8 multi-byte char at 500-byte system prompt boundary",
        "similarity": 0.713639672618987
      },
      {
        "issueNumber": 52486,
        "title": "[BUG] [v0.0.1] agent list description column truncation uses unsafe byte slice d[..35] — panics on non-ASCII descriptions",
        "similarity": 0.7057860800466728
      },
      {
        "issueNumber": 52493,
        "title": "[BUG] [v0.0.1] agent show system prompt preview uses unsafe byte slice prompt[..500] — panics on non-ASCII prompts",
        "similarity": 0.6560503338935657
      },
      {
        "issueNumber": 53405,
        "title": "[BUG] [v0.0.7] cortex mcp list panics with UTF-8 multi-byte char at byte 19 in stdio server command",
        "similarity": 0.6476235648927704
      },
      {
        "issueNumber": 53402,
        "title": "cortex feedback history panics with 'byte index is not a char boundary' for messages with UTF-8 chars near 100-byte mark",
        "similarity": 0.6475206296071528
      }
    ]
  },
  "editHistory": {
    "fraudScore": 0,
    "editCount": 0,
    "details": "No edits detected"
  },
  "codeVerification": {
    "plausible": true,
    "confidence": 1,
    "reasoning": "The code in `src/cortex-cli/src/agent_cmd/handlers/list.rs` truncates the agent description using byte slicing (`&d[..35]`). In Rust, slicing a string at a byte index that does not fall on a UTF-8 character boundary will cause a runtime panic. If a description contains multi-byte characters (like CJK characters) and exceeds 38 bytes, it is highly likely that byte 35 is not a character boundary, leading to the reported panic.",
    "codeEvidence": "let desc = agent\n    .description\n    .as_ref()\n    .map(|d| {\n        if d.len() > 38 {\n            format!(\"{}...\", &d[..35])\n        } else {\n            d.clone()\n        }\n    })",
    "screenshotValid": true,
    "screenshotReasoning": "The screenshot analysis returned valid, indicating it shows the actual panic occurring in the terminal when running the command."
  },
  "llmValidity": {
    "score": 0.050000000000000044,
    "reasoning": "The submission provides excellent documentation of a bug, including clear steps to reproduce, a precise root cause analysis pointing to the exact lines of Rust code, and visual evidence. The issue correctly identifies that using raw byte slicing (`&d[..35]`) on a UTF-8 string containing multi-byte characters causes a panic. However, a review of existing issues reveals that this exact bug in the `agent list` description truncation logic was previously reported in issue #52486. Since the older issue describes the same vulnerability in the same component, this submission must be marked as a duplicate."
  },
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      "You MUST call the deliver_verdict function exactly once. Do not output a JSON object manually. Do not output your verdict in plain text. Use the tool.",
      "Be highly suspicious of submissions that follow a rigid template: same structure, same phrasing, with only the page name or URL swapped. These are template-farmed and should be INVALID. Look for: identical sentence structure, placeholder-like descriptions, formulaic \"Steps to Reproduce\".",
      "When similar issues exist, the OLDER issue (lower issue number) always takes precedence. The newer submission is the duplicate, never the other way around.",
      "Confidence scores must be calibrated: use 0.9+ only when evidence is unambiguous and complete. Use 0.5-0.7 when the issue is borderline. Use below 0.5 when you are genuinely uncertain. Never default to 0.5 — commit to a direction.",
      "Do not give the benefit of the doubt. Missing evidence means INVALID. Unclear reproduction steps means INVALID. Inaccessible media means INVALID. The burden of proof is on the submitter.",
      "In the reasoning field, explain your step-by-step analysis BEFORE stating your conclusion. Cover: evidence quality, clarity, spam signals, and duplicate overlap in that order.",
      "Never mention internal scoring thresholds, rule IDs, detection heuristics, or system architecture in the recap field. The recap is public-facing. Keep reasoning technical but recap user-friendly.",
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      "If the pre-computed media check says media URLs exist, verify the description matches what a screenshot would show. If the description talks about a login page but the context suggests the screenshot is of something unrelated, flag this as suspicious.",
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      "Write your reasoning and recap in a professional, neutral tone. Do not be sarcastic, condescending, or emotional. State facts.",
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}

_{Validated by Atlas • 2026-04-16}