Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, WebSocket FrameTranscoder.bodyLength rejects extended payload lengths above Integer.MAX_VALUE but permits negative 64-bit lengths. A remote client that completes a WebSocket handshake through an Ember server can send such a frame, causing the decoder to return an empty frame without advancing its input. The decode loop then runs indefinitely, pins a worker at full CPU, and grows an ArrayBuffer without bound, resulting in denial of service. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
CVE-2026-69210
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 60% 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
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: 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 computedSeverity75% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 40%
- KEV
- Not listed
Published
September 15, 2026
Last Modified
September 17, 2026
Advisory Details (4)
Auto-updated Sep 15, 2026v1.0.0-M47
Patch available: http4s/http4s v1.0.0-M47 (pre-release)
https://github.com/http4s/http4s/releases/tag/v1.0.0-M47v0.23.35
Patch available: http4s/http4s v0.23.35
https://github.com/http4s/http4s/releases/tag/v0.23.35commit c7d3ef90dc2e (http4s/http4s)
Patch available: http4s/http4s v0.23.35 (contains commit c7d3ef90dc2e)
https://github.com/http4s/http4s/commit/c7d3ef90dc2ed1cd464968ab1b34f2f1762ddae2WebSocket decoder accepts negative length, causing infinite decode loop · Advisory · http4s/http4s · GitHub
https://github.com/http4s/http4s/security/advisories/GHSA-3j86-pj9g-jchrWeakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× 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.
- 2026-09-19 19:17 UTCEG score recompute
- 2026-09-19 07:00 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 06:25 UTCEG score recompute
- 2026-09-17 18:08 UTCEG score recompute
- 2026-09-16 21:05 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-15 20:40 UTCEG score recompute
- 2026-09-15 19:23 UTCEG score recompute
- 2026-09-15 19:22 UTCMITRE cvelistV5first tracked
Frequently asked(5)
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-69210
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