Netty HTTP/3 QPACK Blocked Streams Memory Exhaustion
Priority LOW 39CWE-770Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.
Summary
Netty is a network application framework for development of protocol servers and clients. Starting in version 4.2.0.Final and prior to version 4.2.15.Final, a memory exhaustion vulnerability in the Netty HTTP/3 codec allows the creation of an infinite number of blocked streams, which can cause OOM error. Version 4.2.15.Final patches the issue.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00392 33rd percentileScored 2026-11-07
Fix Partial netty (netty): 4.2.15.Finalio.netty:netty-codec-http3 (Maven): 4.2.15.FinalRed Hat: 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| netty | netty | 4.2.0.Final to before 4.2.15.Final | 4.2.15.Final | Patch available | CNA |
| — | io.netty:netty-codec-http3 (Maven) | 4.2.0.Final to before 4.2.15.Final | 4.2.15.Final | Patch available | GHSA-4grm-h2qv-h6w6 |
- netty Vendornetty Affected 4.2.0.Final to before 4.2.15.Final Fixed in 4.2.15.Final Patch available CNA
- io.netty:netty-codec-http3 (Maven) Vendor— Affected 4.2.0.Final to before 4.2.15.Final Fixed in 4.2.15.Final Patch available GHSA-4grm-h2qv-h6w6
Remediation
- Fix · CNA netty (netty) Fixed in 4.2.15.Final
- Fix · GHSA-4grm-h2qv-h6w6 io.netty:netty-codec-http3 (Maven) Fixed in 4.2.15.Final Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat build of Apache Camel - HawtIO 4 | Affected | — |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-48748
- 2026-10-03 Alias added: GHSA-4grm-h2qv-h6w6
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-10-25 Priority changed: MEDIUM → LOW
References
Advisory 2
Other 6
- https://github.com/netty/netty/commit/75127cab731ee35068d1f0667bffa188bc332f5d
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://access.redhat.com/security/cve/CVE-2026-48748
- https://bugzilla.redhat.com/show_bug.cgi?id=2488441
- https://github.com/netty/netty
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48748.json
More Netty vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
- TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
- TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
- TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
- TI-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
Sources
- CVE-2026-48748 · CVE Program
- CVE-2026-48748 · NVD
- FIRST EPSS
- GHSA-4grm-h2qv-h6w6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-48748 · Red Hat security data · CC BY 4.0
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