CVE-2026-50018

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 77% 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).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Hoverfly is an open source API simulation tool. Prior to version 1.12.8, remote post-serve actions use http.DefaultClient without any timeout configuration. When the remote endpoint is unreachable or intentionally slow (accepts TCP connection but never responds), each triggered proxy request spawns a goroutine that blocks indefinitely on http.DefaultClient.Do(). An attacker can cause unbounded goroutine accumulation leading to memory exhaustion and process crash (OOM kill). Unlike local post-serve action execution, this requires no binary execution, only a URL pointing to a non-responsive endpoint. Version 1.12.8 patches the issue.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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 computed
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

July 14, 2026

Last Modified

September 14, 2026

Advisory Details (3)

Auto-updated Sep 11, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_release.
github_release Patch Available

v1.12.8

Patch available: SpectoLabs/hoverfly v1.12.8

https://github.com/SpectoLabs/hoverfly/releases/tag/v1.12.8
github_pr

fix(action): timeout remote post-serve HTTP client (GHSA-42j2-w334-qxw7)

Fix merged in SpectoLabs/hoverfly PR #1228 on 2026-05-27 — awaiting tagged release

https://github.com/SpectoLabs/hoverfly/pull/1228
github Patch Available🟡 PoC Available

Denial of Service via Goroutine Leak in Remote Post-Serve Actions · Advisory · SpectoLabs/hoverfly · GitHub

https://github.com/SpectoLabs/hoverfly/security/advisories/GHSA-42j2-w334-qxw7

Vendor Advisories for CVE-2026-50018(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)
PackageVulnerable rangeFixed inDependents
github.com/SpectoLabs/hoverfly—1.12.8—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 10× 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.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 04:52 UTCEG score recompute
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-14 20:27 UTCEG score recompute
  6. 2026-09-14 19:35 UTCEG score recompute
  7. 2026-09-14 06:58 UTCEG score recompute
  8. 2026-09-13 16:47 UTCEPSS rescore
  9. 2026-09-13 07:40 UTCEG score recompute
  10. 2026-09-11 23:11 UTCEG score recompute
  11. 2026-07-31 08:18 UTCEG score recompute
  12. 2026-07-26 11:43 UTCEG score recompute
  13. 2026-07-23 03:18 UTCEG score recompute
  14. 2026-07-14 18:10 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-50018?
CVE-2026-50018 is a medium vulnerability published on July 14, 2026. Hoverfly is an open source API simulation tool. Prior to version 1.12.8, remote post-serve actions use http.DefaultClient without any timeout configuration. When the remote endpoint is unreachable or intentionally slow (accepts TCP connection but never responds), each triggered proxy request spawns…
When was CVE-2026-50018 disclosed?
CVE-2026-50018 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-50018 actively exploited?
CVE-2026-50018 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.2% of all scored CVEs.
What is the CVSS score of CVE-2026-50018?
CVE-2026-50018 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-50018?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-50018, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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