CVE-2026-55438: Coder allows organizations to provision remote development environments via Terraform

Routine

MEDIUM 5.8UPGRADE

CVE-2026-55438 is a medium-severity flaw (CVSS 5.8) affecting coder. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the unverified username in

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.8 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-346
Published	2026-07-08
Last modified	2026-07-08

Publisher (CNA): GitHub, Inc. · Vendor: coder

Last updated 2026-07-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-08 01:16 UTCPublished CVE record published
2026-07-08 19:38 UTCUpdated Record last modified

coder coder UPGRADE

Affected: < 2.29.17 · >= 2.30.0 and < 2.32.7 · >= 2.33.0 and < 2.33.8 · >= 2.34.0 and < 2.34.2

Fixed in: 2.29.17, 2.32.7, 2.33.8, 2.34.2

Safe to downgrade to: a release before 2.30.0

1. Check installed version

apt-cache policy coder || rpm -q coder || coder --version

2. UPGRADE to 2.29.17 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade coder

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade coder

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.30.0 (Debian / Ubuntu)

apt-cache madison coder sudo apt install coder=<VERSION_BEFORE_2.30.0> sudo apt-mark hold coder

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list coder sudo dnf downgrade coder-<VERSION_BEFORE_2.30.0> sudo dnf versionlock add coder

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55438?

coder: upgrade to 2.29.17, 2.32.7, 2.33.8, 2.34.2. Exact commands for each OS are on this page.

Is CVE-2026-55438 being exploited?

CVE-2026-55438 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55438 affect?

CVE-2026-55438 affects coder. Severity is medium (CVSS 5.8). 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, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When

How urgent is CVE-2026-55438?

Priority 23/100. No elevated risk signals yet.

Software pages

Terraform vulnerabilities

Related CVEs

CVE-2026-55435 MEDIUM 5.4 UPGRADE Coder allows organizations to provision remote development environments via Terraform
CVE-2026-55077 HIGH 7.2 UPGRADE Coder allows organizations to provision remote development environments via Terraform
CVE-2026-44454 HIGH 8.1 UPGRADE Coder allows organizations to provision remote development environments via Terraform
CVE-2026-55434 MEDIUM 6.5 UPGRADE Coder allows organizations to provision remote development environments via Terraform
CVE-2026-45796 MEDIUM 6.5 UPGRADE Coder allows organizations to provision remote development environments via Terraform

References

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