Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HTTP/2 flow-control window is replenished according to bytes received from the network rather than bytes consumed by the application, while each stream stores DATA in an unbounded channel. A hostile peer can therefore send a body faster than a slow or non-draining application consumes it, retaining payloads in heap on an ember-server or ember-client configured with withHttp2. The patch bounds the per-stream H2Connection body channel so application consumption applies backpressure. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
CVE-2026-69202
HIGHPre-NVD 7.57.5—Trending — 3 sources updated this week
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 62% 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
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.
- 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
- 38%
- KEV
- Not listed
Published
September 15, 2026
Last Modified
September 16, 2026
Advisory Details (4)
Auto-updated Sep 15, 2026Patch 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-M47github_release Patch Available
v0.23.35
Patch available: http4s/http4s v0.23.35
https://github.com/http4s/http4s/releases/tag/v0.23.35github_commit Patch Available
commit 22d2335975d0 (http4s/http4s)
Patch available: http4s/http4s v0.23.35 (contains commit 22d2335975d0)
https://github.com/http4s/http4s/commit/22d2335975d02dc9fb9fb75cfe002279521d86acgithub Patch Available
Ember HTTP/2: unbounded inbound body buffering · Advisory · http4s/http4s · GitHub
https://github.com/http4s/http4s/security/advisories/GHSA-6m4x-pp6q-5jmmVendor Advisories for CVE-2026-69202(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(3 across 1 ecosystem)
Maven(3)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| org.http4s:http4s-ember-core_2.12 | 0.10.0-M10 ... 0.23.9 (114 versions) | 0.23.35 | — |
| org.http4s:http4s-ember-core_2.13 | 0.10.0-M10 ... 0.23.9 (114 versions) | 0.23.35 | — |
| org.http4s:http4s-ember-core_3 | 0.22.0 ... 0.23.9 (58 versions) | 0.23.35 | — |
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.
- 2026-09-19 05:36 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 19:42 UTCEG score recompute
- 2026-09-16 20:04 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-15 20:39 UTCEG score recompute
- 2026-09-15 19:43 UTCEG score recompute
- 2026-09-15 19:33 UTCEG score recompute
- 2026-09-15 19:32 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-69202?
CVE-2026-69202 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, Ember’s HTTP/2 flow-control window is replenished according to bytes received from the network rather than bytes consumed by the application, while each stream stores DATA in an unbounded channel. A hostile peer can…
When was CVE-2026-69202 disclosed?
CVE-2026-69202 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-2026-69202 actively exploited?
CVE-2026-69202 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 62.3% of all scored CVEs.
What is the CVSS score of CVE-2026-69202?
CVE-2026-69202 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-69202?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-69202, 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
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-69202
Is Your Infrastructure Affected by CVE-2026-69202?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.