CVE-2026-48043 Netty
| Affected software | Netty |
|---|---|
| Severity | 7.5 High CVSS 3.1 3 scores |
| Fixed in | 4.1.135.Final, 4.2.15.Final |
| Weakness | Uncontrolled resource consumption (CWE-400) |
| Published | 12 Jun 2026 |
| Updated | 18 Sep 2026 |
Description
Netty is a network application framework for development of protocol servers and clients. In netty-codec-http2 prior to versions 4.1.135.Final and 4.2.15.Final, the DelegatingDecompressorFrameListener class orchestrates HTTP/2 decompression by embedding a per-stream EmbeddedChannel that runs the appropriate decompression codec (gzip, deflate, zstd) and forwards decompressed chunks to a wrapped listener. Each decompressed chunk is a pooled ByteBuf handed to an anonymous ChannelInboundHandlerAdapter tail handler, which becomes the sole owner responsible for releasing it. A remote peer could send frames that would result in the flow-controller throwing and so trigger a resource leak which at the end might take down the whole JVM due OOME. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
CWE-401CWE-772
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 0.75% 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: netty/netty db6138b.
- 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-c2gf-v879-257j : 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
3 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
3 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 |
NVD | Primary | 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 | |
| CVSS 3.1 | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
security-advisories@github.com | Secondary |
Affected software and releases
Maven packages
Affected and fixed versions, from OSV.dev| Package | Introduced | Fixed | Last affected |
|---|---|---|---|
io.netty:netty-codec-http2 |
0 | 4.1.135.Final |
unbounded |
io.netty:netty-codec-http2 |
4.2.0.Alpha1 | 4.2.15.Final |
unbounded |
Products and versions
2 products, 4 version entries| Source | Vendor | Product | Scheme | Affected versions |
|---|---|---|---|---|
| osv | io.netty | netty-codec-http2 | 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. |