CVE-2026-69209

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 71% 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
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The shared WebSocket decoder permits unbounded message buffering because defragmentation accumulates fragments without a limit and FrameTranscoder accepts declared lengths up to Int.MaxValue. A remote client that completes a WebSocket handshake against an http4s-blaze-server or http4s-ember-server endpoint can exhaust server memory with oversized frames or fragmented messages. The patched decoder applies a configurable 64 MiB default limit to individual frames and defragmented messages through EmberServerBuilder.withMaxWebSocketMessageSize. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

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 computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
29%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (4)

Auto-updated Sep 15, 2026
Patch available. Sources: github_release, github, github_commit.
github_release Patch Available

v1.0.0-M47

Patch available: http4s/http4s v1.0.0-M47 (pre-release)

https://github.com/http4s/http4s/releases/tag/v1.0.0-M47
github_release Patch Available

v0.23.35

Patch available: http4s/http4s v0.23.35

https://github.com/http4s/http4s/releases/tag/v0.23.35
github_commit Patch Available

commit d578c3c9da61 (http4s/http4s)

Patch available: http4s/http4s v0.23.35 (contains commit d578c3c9da61)

https://github.com/http4s/http4s/commit/d578c3c9da6193627d40fa785e612cda7fcd77b3
github Patch Available

WebSocket decoder accepts unbounded message sizes · Advisory · http4s/http4s · GitHub

https://github.com/http4s/http4s/security/advisories/GHSA-jrxx-w2m8-5hf5

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 11× 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. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-20 03:22 UTCEG score recompute
  3. 2026-09-19 01:34 UTCEG score recompute
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-17 23:48 UTCEG score recompute
  6. 2026-09-16 19:23 UTCEG score recompute
  7. 2026-09-16 18:52 UTCEG score recompute
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-15 19:32 UTCEG score recompute
  10. 2026-09-15 19:04 UTCEG score recompute
  11. 2026-09-15 19:02 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-69209?
CVE-2026-69209 is a high vulnerability published on September 15, 2026. Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The shared WebSocket decoder permits unbounded message buffering because defragmentation accumulates fragments without a limit and FrameTranscoder accepts declared lengths up to Int.MaxValue. A remote client that…
When was CVE-2026-69209 disclosed?
CVE-2026-69209 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-69209 actively exploited?
CVE-2026-69209 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 71.3% of all scored CVEs.
What is the CVSS score of CVE-2026-69209?
CVE-2026-69209 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-69209?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-69209, 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.

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