Netty QUIC hash collision DoS attack
Priority LOW 31CWE-407Published · 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 · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-407.
Summary
Netty QUIC codec is a QUIC codec for netty which makes use of quiche. An issue was discovered in the codec. A hash collision vulnerability (in the hash map used to manage connections) allows remote attackers to cause a considerable CPU load on the server (a Hash DoS attack) by initiating connections with colliding Source Connection IDs (SCIDs). This vulnerability is fixed in 0.0.71.Final.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0059 48th percentileScored 2026-11-07
Fix Fixed netty-incubator-codec-quic (netty): 0.0.71.Finalio.netty.incubator:netty-incubator-codec-quic (Maven): 0.0.71.Final
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-incubator-codec-quic | before 0.0.71.Final | 0.0.71.Final | Patch available | CNA |
| — | io.netty.incubator:netty-incubator-codec-quic (Maven) | before 0.0.71.Final | 0.0.71.Final | Patch available | GHSA-hqqc-jr88-p6x2 |
- netty-incubator-codec-quic Vendornetty Affected before 0.0.71.Final Fixed in 0.0.71.Final Patch available CNA
- io.netty.incubator:netty-incubator-codec-quic (Maven) Vendor— Affected before 0.0.71.Final Fixed in 0.0.71.Final Patch available GHSA-hqqc-jr88-p6x2
Remediation
- Fix · CNA netty-incubator-codec-quic (netty) Fixed in 0.0.71.Final
- Fix · GHSA-hqqc-jr88-p6x2 io.netty.incubator:netty-incubator-codec-quic (Maven) Fixed in 0.0.71.Final Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2025-29908
- 2026-10-03 Alias added: GHSA-hqqc-jr88-p6x2
References
Other 4
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-2026-64821 Netty 4.2.11 through 4.2.17 QUIC Hostname Verification Bypass CVSS 4.0HIGH 8.7
- TI-2026-64818 Netty HTTP/3 QPACK encoder-stream unbounded memory exhaustion DoS CVSS 4.0HIGH 8.7
Sources
- CVE-2025-29908 · CVE Program
- CVE-2025-29908 · NVD
- FIRST EPSS
- GHSA-hqqc-jr88-p6x2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences