# CVE-2026-55428: Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator > Attackers can hijack network routes by supplying unvalidated AllowedIPs, bypassing authorization checks in the Coder tailnet coordinator. - **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 7 Jul 2026 - **Updated:** 8 Jul 2026 - **Also known as:** GHSA-wrq8-fcv5-8hvp, GO-2026-5915 ## What is CVE-2026-55428? CVE-2026-55428 is a high-severity missing authorization vulnerability in coder, published on 7 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent's `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent's UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes. Weakness: CWE-863 (Incorrect Authorization), CWE-285 (Improper Authorization) ## Which versions are affected by CVE-2026-55428? 10 open source packages ship an affected version, including github.com/coder/coder/v2 and github.com/coder/coder. It affects 1 product. | Package | Ecosystem | 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 | | `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: Coder Coder. ## How do I fix CVE-2026-55428? 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. ## Is CVE-2026-55428 being exploited? There is no known exploitation of CVE-2026-55428 in the wild and no public exploit code. ## Other vulnerabilities in coder - [CVE-2026-46354](https://insights.sbomify.com/CVE-2026-46354/): Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft (critical 9.1) - [CVE-2026-55429](https://insights.sbomify.com/CVE-2026-55429/): Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID (high 8.7) - [CVE-2026-55427](https://insights.sbomify.com/CVE-2026-55427/): Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh` (high 8.3) - [CVE-2024-27918](https://insights.sbomify.com/CVE-2024-27918/): Coder's OIDC authentication allows email with partially matching domain to register (high 8.2) - [CVE-2026-44454](https://insights.sbomify.com/CVE-2026-44454/): Coder vulnerable to workspace auto-creation via crafted URL parameters without user consent (high 8.1) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-55428 and fix it if it is affected. What it is: CVE-2026-55428 is a high-severity missing authorization vulnerability in coder, published on 7 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-55428 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/coder/coder/v2 (Go): affected all versions; fixed in 2.29.17, 2.32.7, 2.33.8, 2.34.2 - github.com/coder/coder/v2 (Go): affected all versions; fixed in 2.29.17 - github.com/coder/coder/v2 (Go): affected all versions; fixed in 2.29.17 - github.com/coder/coder/v2 (Go): affected from 2.30.0; fixed in 2.32.7 - github.com/coder/coder/v2 (Go): affected from 2.30.0; fixed in 2.32.7 - github.com/coder/coder/v2 (Go): affected from 2.33.0; fixed in 2.33.8 - github.com/coder/coder/v2 (Go): affected from 2.33.0; fixed in 2.33.8 - github.com/coder/coder/v2 (Go): affected from 2.34.0; fixed in 2.34.2 - github.com/coder/coder/v2 (Go): affected from 2.34.0; fixed in 2.34.2 - github.com/coder/coder (Go): affected all versions; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-55428/ (Markdown: https://insights.sbomify.com/CVE-2026-55428/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55428 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55428 - OSV: https://osv.dev/vulnerability/CVE-2026-55428 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-55428/ Summaries are generated and may contain mistakes; the official description above is the record.