CVE-2026-55079
Coder 2.24.0 – 2.29.17
Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-55079 is a medium-severity Memory Allocation with Excessive Size Value (CWE-789) vulnerability in Coder Coder. Its CVSS base score is 4.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-6 (Least Privilege) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-42132
Vulnerability Data
Coder allows organizations to provision remote development environments via Terraform. Starting in version 2.24.0 and prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `NewDataBuilder` in `provisionersdk/proto/dataupload.go` allocated a byte slice using the client-supplied `FileSize` from a `DataUpload` message without an…
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upper-bound check. Although the DRPC wire limit is 4 MiB, the `FileSize` value itself was unconstrained. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates `FileSize` against an upper bound (`MaxFileSize = 100 MiB`) before allocation. As a workaround, restrict access to the provisioner daemon serve endpoint to trusted provisioner daemon service accounts.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unbounded allocation from client-supplied FileSize in the provisioner daemon endpoint enables remote denial-of-service via resource exhaustion, which maps to exploitation of a public-facing application (T1190).
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Enforces validation of the client-supplied FileSize value in DataUpload messages before the NewDataBuilder allocates the byte slice, directly blocking the unbounded allocation.
Restricts network access to the provisioner daemon serve endpoint to only trusted service accounts, limiting who can send malicious DataUpload messages.
Ensures provisioner daemon service accounts receive only the minimum privileges required, reducing the attack surface for sending oversized FileSize values.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent coding flaws that trust unvalidated size values for allocations.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect and block excessive allocation flaws before deployment.
Secure development lifecycle includes input validation and size checks that prevent unbounded allocations.
Application security requirements mandate bounds checking on size parameters to avoid excessive memory allocation.
Secure architecture principles require resource-limit enforcement that mitigates uncontrolled memory requests.
Secure coding standards directly prohibit allocating memory from untrusted size values without validation.
Capacity management monitors overall resource use but does not prevent individual allocation bugs.