CVE-2025-12543

criticalpriority · attend · 48EPSS 0.013 · 71 %ileexploit · PoCDEEURUUS
grimoire priorityP1 · Urgent
Exploitable?
Public exploit
1 exploit · PoC
Likely / severe?
1.33% (71st) EPSS
CVSS 9.6 · critical
Is it mine?
116 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The Undertow library fails to properly validate the Host header in incoming HTTP requests.As a result, requests containing malformed or malicious Host headers are processed without rejection, enabling attackers to poison caches, perform internal network scans, or hijack user sessions.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.6
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 6
v3.19.6criticalAV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Lsecondary · FSTEC (BDU) RU
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Lsecondary · ENISA EU
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Lsecondary · secalert@redhat.com USexploitability 2.8 · impact 6
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Lsecondaryexploitability 2.8 · impact 6
v3.19.6criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Lsecondary · OSV
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USCWE-20USCWE-20US
04

exploits (1)

Public proof-of-concept and weaponised exploit code.

05

affected products (116)

Products and version ranges known to be affected.

showing 20 of 116
06

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-0054Red Hat JBoss Enterprise Application Platform (Undertow): Mehrere SchwachstellenDeutsch2026-01-08csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Red Hat JBoss Enterprise Application Platform ausnutzen, um einen Denial of Service Zustand herbeizuführen, Daten zu manipulieren und um weitere Angriffe wie Cache-Poisoning und Session-Hijacking durchzuführen.

  • WID-SEC-W-2026-1194Oracle Communications: Mehrere SchwachstellenDeutsch2026-04-21csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

  • GHSA-j382-5jj3-vw4jUndertow HTTP server core doesn't properly validate the Host header in incoming HTTP requests2026-01-07ghsa · osvUS

    A flaw was found in the Undertow HTTP server core, which is used in WildFly, JBoss EAP, and other Java applications. The Undertow library fails to properly validate the Host header in incoming HTTP requests. As a result, requests containing malformed or malicious Host headers are processed without rejection, enabling attackers to poison caches, perform internal network scans, or hijack user sessions.

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundosvNVDCVE.orgMITRE
published 2026-01-07modified 2026-09-07
09

references (35)

External citations — patches, advisories, analysis.

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