CVE-2026-46354: Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.3%, percentile 23: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 23% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes github.com/coder/coder/v2 (Go) >= 2.33.0-rc.0, < 2.33.3, fixed in 2.33.3; github.com/coder/coder/v2 (Go) >= 2.32.0-rc.0, < 2.32.2, fixed in 2.32.2; github.com/coder/coder/v2 (Go) >= 2.31.0, < 2.31.12, fixed in 2.31.12; github.com/coder/coder/v2 (Go) >= 2.30.0, < 2.30.8, fixed in 2.30.8. Check your lockfile, including transitive dependencies.

What it is

Coder allows organizations to provision remote development environments via Terraform. In versions prior tp 2.24.5, 2.29.13, 2.30.8, 2.31.12, 2.32.2, and 2.33.3, azureidentity.Validate() verifies that the PKCS#7 signer certificate chains to a trusted Azure CA but never verifies the PKCS#7 signature itself. An attacker can embed a legitimate Azure certificate alongside arbitrary content e.g. {"vmId":" "} and the forged vmId will be accepted returning the victim workspace agent's session token. No authentication is required. The attacker only needs to know a target VM's vmId which is a UUIDv4. That's a practical limitation which would typically require prior access to be exploited. Versions 2.24.5, 2.29.13, 2.30.8, 2.31.12, 2.32.2, and 2.33.3 patch the issue. As a workaround, reconfigure any Azure templates to use token authentication rather than azure-instance-identity.

From the GitHub advisory

Summary

azureidentity.Validate() verifies that the PKCS#7 signer certificate chains to a trusted Azure CA but never verifies the PKCS#7 signature itself. An attacker can embed a legitimate Azure certificate alongside arbitrary content e.g. {"vmId":" "} and the forged vmId will be accepted returning the victim workspace agent's session token.

No authentication is required. The attacker only needs to know a target VM's vmId which is a UUIDv4. > that's a practical limitation which would typically require prior access to be exploited

Root Cause

In unpatched Coder releases the signature over the PKCS#7 content is not validated - only the signing certificate is checked.

Weakness type: CWE-347.

Product: github.com/coder/coder/v2 (Go) · Assigned by: GitHub_M · Published: 2026-07-07

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.32% probability of exploitation activity in the next 30 days; percentile 23.

Timeline

• 2026-05-19 — GitHub-reviewed advisory GHSA-6x44-w3xg-hqqf published (critical)
• 2026-07-07 — CVE record published by GitHub_M
• 2026-07-08 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-6x44-w3xg-hqqf github.com
2. CVE.org record CVE-2026-46354 cve.org
3. NVD entry CVE-2026-46354 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
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7. github.com github.com
8. github.com github.com

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