CVE-2026-55437

MEDIUMPre-NVD 5.45.4
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 5.4 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 5.4Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component

Summary

The 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.

> Note: Exploitation requires a victim to view attacker-controlled agent logs in the dashboard.

Impact

A 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.

Patches

The fix enables escapeXML: true so HTML metacharacters are escaped before DOM insertion.

The fix was backported to all supported release lines:

| Release line | Patched version | |---|---| | 2.34 | v2.34.2 | | 2.33 | v2.33.8 | | 2.32 | v2.32.7 | | 2.29 (ESR) | v2.29.17 |

Workarounds

None.

Resources

  • Fix: #25808

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22449) for independently disclosing this issue!

CVSS v3
5.4
EG Score
5.4(low)
EPSS
—
KEV
Not listed

Published

July 6, 2026

Last Modified

July 6, 2026

Vendor Advisories for CVE-2026-55437(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 1× in last 7d / 1× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 21:35 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-55437?
CVE-2026-55437 is a medium vulnerability published on July 6, 2026. Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component Summary The 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…
When was CVE-2026-55437 disclosed?
CVE-2026-55437 was first published in the National Vulnerability Database on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-55437?
CVE-2026-55437 has a CVSS v4.0 base score of 5.4 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55437?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55437, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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