CVE-2026-55437 Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component
Attackers can inject malicious HTML into workspace agent logs, leading to stored XSS when victims view the dashboard, potentially compromising user accounts.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-55437?
CVE-2026-55437 is a medium-severity cross-site scripting vulnerability in coder, published on 8 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-55437?
10 open source packages ship an affected version, including github.com/coder/coder/v2 and github.com/coder/coder. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/coder/coder/v2 Go | All versions | 2.29.17, 2.32.7, 2.33.8, 2.34.2 |
github.com/coder/coder/v2 Go | All versions | 2.29.17 |
github.com/coder/coder/v2 Go | All versions | 2.29.17 |
github.com/coder/coder/v2 Go | From 2.30.0 | 2.32.7 |
github.com/coder/coder/v2 Go | From 2.30.0 | 2.32.7 |
github.com/coder/coder/v2 Go | From 2.33.0 | 2.33.8 |
4 more packages
github.com/coder/coder/v2 Go | From 2.33.0 | 2.33.8 |
github.com/coder/coder/v2 Go | From 2.34.0 | 2.34.2 |
github.com/coder/coder/v2 Go | From 2.34.0 | 2.34.2 |
github.com/coder/coder Go | All versions | None |
Products include Coder Coder.
How do I fix CVE-2026-55437?
Upgrade github.com/coder/coder/v2 to a fixed version for your release line: 2.29.17, 2.32.7, 2.33.8 or 2.34.2.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-55437 being exploited?
There is no known exploitation of CVE-2026-55437 in the wild and no public exploit code.
Other vulnerabilities in coder
- CVE-2026-46354 Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft
- CVE-2026-55429 Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID
- CVE-2026-55427 Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
- CVE-2026-55428 Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator
- CVE-2024-27918 Coder's OIDC authentication allows email with partially matching domain to register
Sources
Also known as GHSA-7qw2-f75v-62f7, GO-2026-5919.