Skip to content
Noroxi
CVE-2026-55431· NVD / CVE Program· CNA GitHub_M

Coder's session token leaked to arbitrary hosts via `coder open app` for external workspace apps

Noroxi assessment

Priority: Monitor (action score 24/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.33% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: github.com/coder/coder/v2 (Go) 2.32.7, 2.33.8, 2.34.2.

Low priority for now. Upgrade to github.com/coder/coder/v2 (Go) 2.32.7, 2.33.8, 2.34.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

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, `coder open app` opens external workspace-app URLs without validating the scheme or host. When an external app URL contains the `$SESSION_TOKEN` placeholder the CLI replaces it with the user's real session token before handing the URL to the OS open handler. Practical exploitation requires the victim to run `coder open app` against a workspace whose external app definition the attacker controls. Only a malicious template author can control external app URLs. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 applies a URL-scheme allowlist in the CLI and limits `$SESSION_TOKEN` substitution to trusted destinations like the web frontend. As a workaround, avoid running `coder open app` for untrusted workspaces.

MediumCVSS 6.1 · v3.1—No exploit Fix available
Published
Jul 7, 2026
Updated
Jul 8, 2026
EPSS
0.3% · 25th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.1
CNA · GitHub_M
7.7
1.6 point gap

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-55431

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Port scanning: 5 full scans a day (members only)
  • Uptime monitoring: 1 site, instant email when it goes down
  • Verify your domain: subdomains and takeover risk scanned every week
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for coder records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
codercoder

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • coder coderbefore 2.29.17
  • coder coder2.30.0 and later · before 2.32.7
  • coder coder2.33.0 and later · before 2.33.8
  • coder coder2.34.0 and later · before 2.34.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • coder coder

    • >= 2.34.0, < 2.34.2, >= 2.33.0, < 2.33.8, >= 2.30.0, < 2.32.7, < 2.29.17affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/coder/coderall versions—
Gogithub.com/coder/coder/v2from 2.30.0 · before 2.32.72.32.7
Gogithub.com/coder/coder/v2from 2.33.0 · before 2.33.82.33.8
Gogithub.com/coder/coder/v2from 2.34.0 · before 2.34.22.34.2
Gogithub.com/coder/coder/v2before 2.29.172.29.17

Same product

coder: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-46354Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft
    36Monitor
  • CVE-2026-44454Coder vulnerable to workspace auto-creation via crafted URL parameters without user consent
    36Monitor
  • CVE-2026-55429Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID
    34Monitor
  • CVE-2026-63443Coder: Workspace agent API insecure redirect handling allowed cross-agent file read and write
    33Monitor
  • CVE-2026-55427Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh`
    33Monitor
  • CVE-2026-55428Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/coder/coder/v22.29.17Package registry (OSV)
Go:github.com/coder/coder/v22.32.7Package registry (OSV)
Go:github.com/coder/coder/v22.33.8Package registry (OSV)
Go:github.com/coder/coder/v22.34.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-522 · Insufficiently Protected Credentials

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records