# CVE-2026-55078 — coder

> As of 2026-07-07, CVE-2026-55078 is a MEDIUM-severity vulnerability in coder, CVSS v3.1 6.5. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-55078 as of 2026-07-07; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-07

## What is CVE-2026-55078?

Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.17.0 and prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `POST /api/v2/files` converts zip uploads to tar in memory via `CreateTarFromZip`, which enforced a per-entry size limit but no aggregate limit on total decompressed output, writing to an unbounded in-memory buffer. Exploitation requires authenticated file-upload access and the impact is limited to availability (denial of service). The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 adds a metadata preflight check that sums projected entry sizes and a streaming writer that enforces the aggregate limit during decompression. As a workaround, restrict file-upload permissions to trusted users or place a reverse proxy with request-body size limits in front of `coderd`.

The record classifies CVE-2026-55078 under weakness classes [CWE-409](https://cwe.mitre.org/data/definitions/409.html), [CWE-770](https://intel.threadlinqs.com/cwe/CWE-770). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 90 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.5 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-07

## Is CVE-2026-55078 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **coder**: coder

Affected software packages:

- `go:github.com/coder/coder/v2` — patched in 2.34.2
- `go:github.com/coder/coder/v2` — patched in 2.33.8
- `go:github.com/coder/coder/v2` — patched in 2.32.7
- `go:github.com/coder/coder/v2` — patched in 2.29.17

## How to fix CVE-2026-55078

Fixed versions are recorded for 4 packages: go:github.com/coder/coder/v2 2.34.2, go:github.com/coder/coder/v2 2.33.8, go:github.com/coder/coder/v2 2.32.7, go:github.com/coder/coder/v2 2.29.17. No vendor patch reference has been recorded for CVE-2026-55078 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-55078

No threat campaign in the Threadlinqs corpus currently references CVE-2026-55078, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-09. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/coder/coder/security/advisories/GHSA-2mg2-p7r7-g27f)

**Other references**

- [github.com](https://github.com/coder/coder/pull/25877)
- [github.com (v2.29)](https://github.com/coder/coder/releases/tag/v2.29.17)
- [github.com (v2.32)](https://github.com/coder/coder/releases/tag/v2.32.7)
- [github.com (v2.33)](https://github.com/coder/coder/releases/tag/v2.33.8)
- [github.com (v2.34)](https://github.com/coder/coder/releases/tag/v2.34.2)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-55078
Full detection coverage and IOCs for threats exploiting CVE-2026-55078 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp