Medium
undertow — security advisory
A flaw was found in the ChunkReader component of the Undertow HTTP server, which is used by WildFly and JBoss EAP to handle chunked transfer encoding. The issue occurs because the parser uses a single internal variable to store both the remaining chunk size and state flags. By sending a specially crafted request with an extremely large chunk size, an attacker can cause these values to overlap, tricking the parser into thinking a request has finished prematurely. This can allow a second, "smuggled" request to be processed out of sync, potentially bypassing security controls.
- Products
- undertow
- Affected versions
- 1.3.11-1, 1.3.16-1, 1.3.16-1ubuntu0.1~esm1, 1.3.4-1, 1.3.5-1, 1.3.7-1, 1.4.20-1, 1.4.21-1, 1.4.22-1, 1.4.23-1, 1.4.23-2build1, 1.4.23-3, 1.4.23-3ubuntu0.1~esm1, 2.0.23-1, 2.0.27-1, 2.0.28-1, 2.0.29-1, 2.0.29-1ubuntu0.1~esm1, 2.2.12-1, 2.2.13-1, 2.2.14-1, 2.2.16-1, 2.2.16-1ubuntu0.1~esm1, 2.2.8-1, 2.3.18-2, 2.3.20-1, 2.3.20-1ubuntu1, 2.3.8-2, 2.3.8-2ubuntu0.1~esm1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-14180
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:41 UTC · Revision 1
Source evidence
A flaw was found in the ChunkReader component of the Undertow HTTP server, which is used by WildFly and JBoss EAP to handle chunked transfer encoding. The issue occurs because the parser uses a single internal variable to store both the remaining chunk size and state flags. By sending a specially crafted request with an extremely large chunk size, an attacker can cause these values to overlap, tricking the parser into thinking a request has finished prematurely. This can allow a second, "smuggled" request to be processed out of sync, potentially bypassing security controls.
osv:UBUNTU-CVE-2026-14180
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
undertow
Fixed versions: Not specified
Complete source record
{
"id": "468af8229aff2a9e89276f63d88f3f515135529b1f07e6028124dab149f2b793",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-14180",
"method": "structured",
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"modified": "2026-10-17T12:58:45.829821854Z",
"provider": "osv",
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"references": [
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"https://www.cve.org/CVERecord?id=CVE-2026-14180",
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"published_at": "2026-08-11T16:17:00+00:00"
}