CVE-2026-46340 Netty
| Affected software | Netty |
|---|---|
| Severity | 7.5 High CVSS 3.1 2 scores |
| Fixed in | 4.2.15.Final, 4.1.135.Final |
| Weakness | CWE-770 |
| Published | 12 Jun 2026 |
| Updated | 18 Sep 2026 |
Description
Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does fragments.put(streamId, Unpooled.wrappedBuffer(frag, byteBuf)), wrapping the previous accumulator and the new slice into a *new* CompositeByteBuf every time. After N fragments the accumulator is an N-deep chain of composites, each holding references and component arrays; readableBytes()/getBytes() on the final buffer recurse N levels. There is no limit on N, on total bytes, or on the number of streamIdentifiers an attacker can open (each gets its own map entry). A peer that never sets the complete flag can grow this structure indefinitely from tiny 1-byte DATA chunks. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Exploitation status
No public exploit
No exploit has been reported in the sources we check.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment exploitation: none
- Indexed PoC none indexed
- EPSS 0.61% chance in 30 days
Waratek protection
Within Waratek scope. In the sources we check, nobody has published exploit code for this CVE or reported it being exploited.
A public code fix exists.
- Protection none
- Action unverified
- Review automated Upstream data
- Record active
| Decided by | Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all |
|---|---|
| Finding | This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious. |
| Candidate fix | https://github.com/netty/netty/security/advisories/GHSA-5xrh-qmmq-w6ch : the maintainers' own security advisory: names the version that fixes it, so the fix is the difference between two releases |
CVSS
7.5 HIGH
v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2 metrics
CVSS
7.5 HIGH v3.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2 metrics
We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.
| Version | Score | Band | Vector | Assigner | Type | |
|---|---|---|---|---|---|---|
| CVSS 3.1 | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
security-advisories@github.com | Secondary | published |
| CVSS 3.1 | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
redhat-SADP | Secondary |
Affected software and releases
Maven packages
Affected and fixed versions, from OSV.dev| Package | Introduced | Fixed | Last affected |
|---|---|---|---|
io.netty:netty-transport-sctp |
4.2.0.Final | 4.2.15.Final |
unbounded |
io.netty:netty-transport-sctp |
0 | 4.1.135.Final |
unbounded |
Products and versions
2 products, 4 version entries| Source | Vendor | Product | Scheme | Affected versions |
|---|---|---|---|---|
| osv | io.netty | netty-transport-sctp | generic | ＜ 4.1.135 · ≥ 4.2.0 and ＜ 4.2.15 |
| nvd | netty | netty | generic | ＜ 4.1.135 · ≥ 4.2.0 and ＜ 4.2.15 |
References
Timeline
Timeline
| Published | 2026-06-12 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-09-18 | NVD's own last-modified date for this record. |