Vulnerability · CVE-2026-14180
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.
Published Aug 11, 2026 · catalog updated Oct 20, 2026 · A flaw was found
Open the advisory
Exploitation likelihood is not on this record for CVE-2026-14180. A missing EPSS score is not a low risk. Compare A flaw was found with the linked advisory before you change production.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (A flaw was found).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- Medium5.3
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Awaiting synchronization with FIRST
- Remediation
- Advisory link
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-14180
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2026-14180. A missing EPSS score is not a low risk. Compare A flaw was found with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-444: HTTP Request Smuggling. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Aug 11, 2026 · NIST NVD
Detected
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, tri
Oct 20, 2026 · NIST NVD
Updated
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, tri
Sources
- NIST NVDVulnerability recordCVE-2026-14180
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 se
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 20, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.