CVE-2026-55437: coder Cross-site Scripting
Vulnerability summary
CVE-2026-55437 is a medium (CVSS 5.4) Cross-site Scripting vulnerability in coder. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 23% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 08-07-2026PublishedVulnerability first disclosed.
- 08-07-2026Last modifiedVulnerability information updated.
Description
Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, 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. Exploitation requires a victim to view attacker-controlled agent logs in the dashboard. The fix in versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2 enables `escapeXML: true` so HTML metacharacters are escaped before DOM insertion. No known workarounds are available.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · GoEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS trend
Probability
0.32%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
0.00 pp
From 0.32% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Coder1 product
- coder< 2.29.17 | ≥ 2.30.0, < 2.32.7 | ≥ 2.33.0, < 2.33.8 | ≥ 2.34.0, < 2.34.2
Github.com/coder1 product
- coderAll versions (No fix recorded)
Github.com/coder/coder1 product
- v2≥ 2.33.0, < 2.33.8 | ≥ 2.30.0, < 2.32.7 | < 2.29.17 | ≥ 2.34.0, < 2.34.2
3 vendors · 3 products
References
7 links- github.com/coder/coder/security/advisories/GHSA-7qw2-f75v-62f7X Refsource CONFIRMWEBAdvisoryPatchVendor Advisory
- github.com/coder/coderPACKAGE