CVE-2026-48059: Netty HAProxy · Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Memory Exhaustion
Affects io.netty:netty-codec-haproxySource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 4.2.15.Final soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.2.15.Final, 4.1.135.Final
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade io.netty:netty-codec-haproxy to 4.2.15.Final; io.netty:netty-codec-haproxy to 4.1.135.Final.
Patches and advisories
- access.redhat.com/errata/RHSA-2026:66488 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65126 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54435 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53806 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53646 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53645 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53644 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50085 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:48151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41951 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37390 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36820 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mavenio.netty:netty-codec-haproxy | Affected
| Fixed in
|
| Mavenio.netty:netty-codec-haproxy | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Impact The HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested `PP2_TYPE_SSL` TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path — no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the `HAProxyMessage` normally. Yet the underlying cumulation buffer (a pooled, potentially direct `ByteBuf` allocated by the channel) remains permanently pinned.
References
- github.com/netty/netty/security/advisories/GHSA-h2qv-fj59-j46j (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-48059 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48059.json (opens in a new tab)
- github.com/netty/netty/releases/tag/netty-4.2.15.Final (opens in a new tab)
- github.com/netty/netty/releases/tag/netty-4.1.135.Final (opens in a new tab)
- github.com/netty/netty (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2488437 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-48059 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:66488 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65126 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54435 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53806 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53646 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53645 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:53644 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50085 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:48151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41951 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37390 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36820 (opens in a new tab)