{"id":"CVE-2026-55437","aliases":["GHSA-7qw2-f75v-62f7"],"title":"Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component","summary":"Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component","severity":"medium","cvss":5.4,"cwe":["CWE-79"],"vendor":"coder","product":"github.com/coder/coder/v2","ecosystem":"go","affected":["github.com/coder/coder/v2 >= 2.34.0, < 2.34.2","github.com/coder/coder/v2 >= 2.33.0, < 2.33.8","github.com/coder/coder/v2 >= 2.30.0, < 2.32.7","github.com/coder/coder/v2 < 2.29.17"],"patched":["github.com/coder/coder/v2 2.34.2","github.com/coder/coder/v2 2.33.8","github.com/coder/coder/v2 2.32.7","github.com/coder/coder/v2 2.29.17"],"published":"2026-07-06","updated":"2026-07-06","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-7qw2-f75v-62f7","references":[{"url":"https://github.com/coder/coder/security/advisories/GHSA-7qw2-f75v-62f7"},{"url":"https://github.com/coder/coder/pull/25808"},{"url":"https://github.com/advisories/GHSA-7qw2-f75v-62f7"}],"tags":["ghsa","go"],"ingestedAt":"2026-07-06T21:45:52.943Z","epss":0.00316,"epssPercentile":0.24682,"slug":"CVE-2026-55437","body":"## Overview\n\n### Summary\n\nThe `AgentLogLine` dashboard component instantiated `ansi-to-html` without `escapeXML: true` and inserted the result via `dangerouslySetInnerHTML` so HTML embedded in workspace agent log lines was rendered as live markup. Server-side sanitization did not neutralize HTML metacharacters.\n\n> **Note:** Exploitation requires a victim to view attacker-controlled agent logs in the dashboard.\n\n### Impact\n\nA user who could run a workspace could emit arbitrary HTML into agent logs; when another user, including an administrator, viewed the workspace page, it rendered in their session. Content Security Policy blocked inline scripts but an attacker could still inject a `meta refresh` redirect, `style` rules for UI redressing or CSS-based exfiltration or external `img` beacons. This required workspace-owner access and a victim viewing the page.\n\n### Patches\n\nThe fix enables `escapeXML: true` so HTML metacharacters are escaped before DOM insertion.\n\nThe fix was backported to all supported release lines:\n\n| Release line | Patched version |\n|---|---|\n| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |\n| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |\n| 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) |\n| 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) |\n\n### Workarounds\n\nNone.\n\n### Resources\n\n- Fix: #25808\n\n### Credits\n\nCoder would like to thank Anthropic's Security Team (ANT-2026-22449) for independently disclosing this issue!\n\n## Affected packages\n\n- `github.com/coder/coder/v2 >= 2.34.0, < 2.34.2`\n- `github.com/coder/coder/v2 >= 2.33.0, < 2.33.8`\n- `github.com/coder/coder/v2 >= 2.30.0, < 2.32.7`\n- `github.com/coder/coder/v2 < 2.29.17`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/coder/coder/v2 2.34.2`\n- `github.com/coder/coder/v2 2.33.8`\n- `github.com/coder/coder/v2 2.32.7`\n- `github.com/coder/coder/v2 2.29.17`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}