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NVD / CVE Program· CNA GitHub_M

CVE-2026-63443: Coder: Workspace agent API insecure redirect handling allowed cross-agent file read and write

Noroxi assessment

Priority: Monitor (action score 33/100)

  • 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: 0.76% (FIRST EPSS); higher than 55.6% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: github.com/coder/coder/v2 (Go) 2.29.19, 2.32.9, 2.33.10.

Low priority for now. Upgrade to github.com/coder/coder/v2 (Go) 2.29.19, 2.32.9, 2.33.10 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

Primary sources: NVD · CVE.org · FIRST EPSS

Coder allows organizations to provision remote development environments via Terraform. Prior to 2.29.19, 2.32.9, 2.33.10, and 2.34.4, agentConn.apiClient() follows redirects while its custom transport accepts the host from the redirected request URL when the port is the workspace agent HTTP API port 4. An authenticated user who controls a modified workspace agent and knows another online agent's UUID can derive the victim's tailnet address and redirect control-plane requests to that agent. HTTP 301, 302, and 303 redirects can redirect read requests, while HTTP 307 and 308 preserve replayable write and process-start requests. The redirected workspace agent file APIs can read or write files as the victim workspace user, and affected versions exposing the workspace agent process API can execute commands after a redirected file write, crossing workspace and tenant boundaries. This issue is fixed in versions 2.29.19, 2.32.9, 2.33.10, and 2.34.4.

HighCVSS 8.3 · v3.1—No exploit Fix available
Published
Sep 15, 2026
Updated
Sep 30, 2026
EPSS
0.7% · 55th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.3
NVD has not scored this yet; the score shown is the CNA’s.

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.

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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

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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.

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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.

—

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

    • >= 2.27.0, < 2.29.19, >= 2.30.0, < 2.32.9, >= 2.33.0, < 2.33.10, >= 2.34.0, < 2.34.4affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Gogithub.com/coder/coderfrom 0—
Gogithub.com/coder/coder/v2from 2.27.0 · before 2.29.192.29.19
Gogithub.com/coder/coder/v2from 2.30.0 · before 2.32.92.32.9
Gogithub.com/coder/coder/v2from 2.33.0 · before 2.33.102.33.10
Gogithub.com/coder/coder/v2from 2.34.0 · before 2.34.42.34.4

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-2026-111927Coder before 2.35.4 Credential Theft via Workspace Proxy Hostname Prefix Match
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-55437Jul 7, 2026 · Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component
    21Monitor
  • ← EarlierCVE-2026-55438Jul 7, 2026 · Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing
    27Monitor
  • Later →CVE-2024-58398Oct 17, 2026 · Coder 2.3.1 before 2.16.1 Open Redirect via Login Page redirect Parameter
    21Monitor

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/v22.29.19Package registry (OSV)
Go:github.com/coder/coder/v22.32.9Package registry (OSV)
Go:github.com/coder/coder/v22.33.10Package registry (OSV)
Go:github.com/coder/coder/v22.34.4Package 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.

  • CVE-2026-11192932 days apartCoder 2.30.0 before 2.34.8 Cross-Organization File Disclosure via DownloadFile RPC
    24Monitor
  • CVE-2026-11192832 days apartCoder 2.0.0 before 2.34.8 Authorization Bypass via User-Level ACL in RBAC Policy
    21Monitor
  • CVE-2026-5543570 days apartSuspended Coder users retain access to AI Bridge LLM proxy endpoints
    21Monitor

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.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
Low

Weakness class (CWE)

CWE-863 · Incorrect Authorization

CVSS vector

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

nvd-secondary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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

References

Show all references (14 more)

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

All records