OpenCost provides cost monitoring for Kubernetes workloads and cloud costs. Prior to 1.121.0, the POST /serviceKey endpoint in pkg/costmodel/router.go allows a network client to invoke AddServiceKey without mandatory authentication and submit an arbitrary key form value that is written to the GCP service-account key.json file returned by GetGCPAuthSecretFilePath in core/pkg/env/core.go. The attacker controls the file contents but not the CONFIG_PATH-derived directory, the key.json filename, or the file mode. Replacing the credential contents can disrupt GCP cost collection or cause OpenCost to use attacker-selected credentials, and the wildcard Access-Control-Allow-Origin response permits browser-assisted requests when the service is reachable from a browser. This issue is fixed in version 1.121.0.
CVE-2026-44300
This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(medium)
- EG Risk
- 55(Track)EG Risk 55/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 35%
- KEV
- Not listed
Published
July 14, 2026
Last Modified
September 15, 2026
Advisory Details (7)
Auto-updated Sep 15, 2026v1.121.0
Patch available: opencost/opencost v1.121.0
https://github.com/opencost/opencost/releases/tag/v1.121.0v1.120.0
Patch available: opencost/opencost v1.120.0
https://github.com/opencost/opencost/releases/tag/v1.120.0commit a49a25bc2e0d (opencost/opencost)
Patch available: opencost/opencost v1.121.0 (contains commit a49a25bc2e0d)
https://github.com/opencost/opencost/commit/a49a25bc2e0d6e220a131a4dc58f38ebe6ae851bcommit 69430e7f627b (opencost/opencost)
Patch available: opencost/opencost v1.120.0 (contains commit 69430e7f627b)
https://github.com/opencost/opencost/commit/69430e7f627b3e62c8999312c06949267fab813adeactivate endpoints unless admin token set
Patch available: opencost/opencost v1.121.0 (PR #3910 merged 2026-07-09)
https://github.com/opencost/opencost/pull/3910add middleware for auth
Patch available: opencost/opencost v1.120.0 (PR #3651 merged 2026-03-12)
https://github.com/opencost/opencost/pull/3651OpenCost ServiceKey Endpoint Unauthorized Credential Overwrite/Injection · Advisory · opencost/opencost · GitHub
https://github.com/opencost/opencost/security/advisories/GHSA-wmj8-9953-vff5Vendor Advisories for CVE-2026-44300(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/opencost/opencost | — | 1.119.1 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 04:53 UTCEG score recompute
- 2026-09-17 19:31 UTCEPSS rescore
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-15 20:47 UTCEG score recompute
- 2026-09-15 19:50 UTCEG score recompute
- 2026-09-15 18:36 UTCEG score recompute
- 2026-09-15 17:23 UTCEG score recompute▲ 8.80
- 2026-09-15 17:22 UTCMITRE cvelistV5CVSS v3 → 8.8 · CVSS v4 → 8.8
- 2026-08-01 12:48 UTCEG score recompute
- 2026-07-26 11:44 UTCEG score recompute
- 2026-07-23 03:15 UTCEG score recompute
- 2026-07-14 17:10 UTCEG score recompute
Frequently asked(5)
What is CVE-2026-44300?
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Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-44300
Is Your Infrastructure Affected by CVE-2026-44300?
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