GHSA-563q-j3cm-6jxm
Suggest an improvement- Source
- https://github.com/advisories/GHSA-563q-j3cm-6jxm
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-563q-j3cm-6jxm/GHSA-563q-j3cm-6jxm.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-563q-j3cm-6jxm
- Aliases
-
- CVE-2026-50560
- Downstream
- Related
- Published
- 2026-06-15T20:46:56Z
- Modified
- 2026-06-16T14:44:20.964765335Z
- Severity
-
- 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
- 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature
- Details
-
Summary
Netty HTTP/2 max header size handling produces attack similar to HTTP/2 Rapid Reset.
Details
There is a setting in the http2 specification called
SETTINGS_MAX_HEADER_LIST_SIZE. According to the RFC: “This advisory setting informs a peer of the maximum field section size that the sender is prepared to accept, in units of octets.”When a client sends that setting to Netty, it appears that Netty will behave as follows:
- Read the request
- Proxy the request to the origin
- Attempt to produce a response
- Create an exception while writing the headers for the response
Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature.
Remediation
When speaking with clients, Netty should potentially treat this as “advisory” and ignore it. It would be best to ignore the SETTINGSMAXHEADERLISTSIZE setting from clients (or ignore it when sending to clients). According to the spec, a server does not need to honor this advisory setting, and it appears that other http/2 implementations ignore it when acting as a server.
Impact
This is a DDoS attack similar to the HTTP/2 Rapid Reset Attack.
Credit
Jonathan Looney (Engineering, Netflix)
Contact
Ashley Tolbert (Security, Netflix) - artolbert@netflix.com
- Database specific
{ "nvd_published_at": "2026-06-12T16:16:32Z", "github_reviewed_at": "2026-06-15T20:46:56Z", "github_reviewed": true, "severity": "MODERATE", "cwe_ids": [ "CWE-770" ] }- References
-
- https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm
- https://nvd.nist.gov/vuln/detail/CVE-2026-50560
- https://github.com/netty/netty
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://www.rfc-editor.org/rfc/rfc9113.html#name-defined-settings
Affected packages
Maven / io.netty:netty-codec-http2
Package
- Name
- io.netty:netty-codec-http2
- View open source insights on deps.dev
- Purl
- pkg:maven/io.netty/netty-codec-http2
Maven / io.netty:netty-codec-http2
Package
- Name
- io.netty:netty-codec-http2
- View open source insights on deps.dev
- Purl
- pkg:maven/io.netty/netty-codec-http2
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed4.1.135.Final