Netty (io.netty:netty-codec-http) contains an unbounded per-connection queue growth flaw in HttpServerCodec. The codec tracks the HTTP method of each still-unanswered pipelined request; the first 32 entries are bit-packed into a single long, but every additional entry is appended to methodOverflowQueue, an ArrayDeque with no size limit and no rejection path. A remote, unauthenticated attacker who pipelines HTTP/1.1 requests on a single connection while withholding reads on their own end (preventing responses from being flushed) can grow this queue without bound, causing unbounded heap growth and denial of service. Affected versions are 4.2.0.Final through 4.2.17.Final and all releases up to and including 4.1.137.Final; the issue is fixed in 4.2.18.Final and 4.1.138.Final.
This CVE has been withdrawn by MITRE
MITRE marked CVE-2026-100656 as REJECTED on . It is no longer considered a valid vulnerability record. The original content below is preserved for historical reference only.
Reason given by MITRE
This CVE ID has been rejected as a duplicate.
CVE-2026-100656
✕ Withdrawn — historical dataHIGHPre-NVD 7.5
7.5CVSS
- CVSS v3
- 7.5
- EchelonGraph score
- Not yet assessedThis CVE record was withdrawn by its numbering authority, so there is no vulnerability to rate.
- EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- —Not applicable: this CVE ID was withdrawn
Published
September 26, 2026
Last Modified
September 28, 2026
References (2)
- disclosure@vulncheck · CISA-ADPhttps://github.com/netty/netty/security/advisories/GHSA-pvjx-v7vp-62vq
- disclosure@vulncheckhttps://www.vulncheck.com/advisories/netty-httpservercodec-unbounded-queue-growth-via-http-1.1-pipelining
Frequently asked(4)
What is CVE-2026-100656?
CVE-2026-100656 is a rejected CVE ID: its record was withdrawn on September 28, 2026 and no longer describes a vulnerability. Reason given: This CVE ID has been rejected as a duplicate.
When was the CVE record for CVE-2026-100656 published?
The CVE record for CVE-2026-100656 was published on September 26, 2026. EchelonGraph's copy of the record carries a last-modified date of September 28, 2026; the record at its source may have been updated since.
What is the CVSS score of CVE-2026-100656?
CVE-2026-100656 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100656?
There is nothing to remediate under CVE-2026-100656: it is a rejected (withdrawn) CVE ID and no longer describes a vulnerability.