Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
GHSA-2c5c-chwr-9hqw affects the Netty package netty-codec-http3 in versions 4.2.0.Final up to but not including 4.2.13.Final. A remote attacker who can send HTTP/3 HEADERS frames to a server can cause it to allocate very large byte arrays from a small crafted header, which can slow, stall or crash the server under load. Upgrade to 4.2.13.Final or later. No workaround is listed.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0044, the 38th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:17 UTC First seen by agentprime
- 31 Oct 2026, 14:17 UTC Confirmed by OSV