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.
CVE-2026-69209
“—” beside the score: it is equal to the CVSS score beside it.
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6% (50th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-79173 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 49EG Risk 49/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity75% × 45%Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.6% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.6%
- EPSS %ILE
- 50th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
September 15, 2026
Last Modified
September 16, 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 d578c3c9da61 (http4s/http4s)
Patch available: http4s/http4s v0.23.35 (contains commit d578c3c9da61)
https://github.com/http4s/http4s/commit/d578c3c9da6193627d40fa785e612cda7fcd77b3WebSocket decoder accepts unbounded message sizes · Advisory · http4s/http4s · GitHub
https://github.com/http4s/http4s/security/advisories/GHSA-jrxx-w2m8-5hf5Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 46× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
- 2026-10-27 20:01 UTCEG score recompute
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-25 14:09 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-20 09:07 UTCEG score recompute
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-18 03:19 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 48th percentile
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- 2026-10-13 09:55 UTCEG score recompute
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-12 15:44 UTCEG score recompute
- 2026-10-11 19:29 UTCEG score recompute
- 2026-10-11 16:45 UTCEG score recompute
- 2026-10-11 14:05 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-11 06:40 UTCEG score recompute
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-10 04:50 UTCEG score recompute
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-09 01:04 UTCEG score recompute
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-08 12:11 UTCEG score recompute
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-06 20:38 UTCEG score recompute
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-05 18:52 UTCEG score recompute
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-05 05:54 UTCEG score recompute
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-03 15:09 UTCEG score recompute
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-03 02:10 UTCEG score recompute
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-10-02 00:15 UTCEG score recompute
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-09-30 22:04 UTCEG score recompute
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-09-29 20:18 UTCEG score recompute
- 2026-09-29 07:23 UTCEG score recompute
- 2026-09-28 18:30 UTCEG score recompute
- 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-09-27 16:00 UTCEG score recompute
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-09-27 03:07 UTCEG score recompute
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 48th percentile
- 2026-09-26 01:08 UTCEG score recompute
- 2026-09-24 23:20 UTCEG score recompute
- 2026-09-23 21:34 UTCEG score recompute
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-22 19:48 UTCEG score recompute
- 2026-09-22 06:55 UTCEG score recompute
- 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-21 05:08 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-20 03:22 UTCEG score recompute
- 2026-09-19 01:34 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-17 23:48 UTCEG score recompute
- 2026-09-16 19:23 UTCEG score recompute
- 2026-09-16 18:52 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-15 19:32 UTCEG score recompute
- 2026-09-15 19:04 UTCEG score recomputeFirst assessed: 7.5 HIGH
- 2026-09-15 19:02 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-69209?
When was the CVE record for CVE-2026-69209 published?
Is CVE-2026-69209 actively exploited?
What is the CVSS score of CVE-2026-69209?
How do I remediate CVE-2026-69209?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-69209
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