Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Netty's netty-codec-classes-quic package, versions 4.2.0.Final up to but not including 4.2.15.Final, is affected. When the application does not set a QUIC token handler, the default handler accepts any client-supplied token as valid. A remote attacker who can send packets with a spoofed source address can then make the server skip address validation and send full-size handshake responses to the victim without the usual amplification limit. Upgrade to 4.2.15.Final or later.
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:H/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0014, the 3rd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:16 UTC First seen by agentprime
- 31 Oct 2026, 14:16 UTC Confirmed by OSV