CVE-2026-89117

Executive Summary

CVE-2026-89117 is a reflected cross-site scripting (XSS) vulnerability in SAP NetWeaver Enterprise Portal (CWE-79, CVSS 3.1 base score 6.1) that allows an unauthenticated attacker to inject malicious scripts into a URL parameter. The injected script is reflected in the server response and executes in the victim's browser when the crafted URL is visited, enabling session information theft, portal content manipulation, or redirection of the user. Impact is scoped to confidentiality and integrity (both Low) with no availability impact; successful exploitation requires user interaction per the CVSS vector.

Technical Analysis

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation — "Cross-site Scripting"). Per the NVD description, SAP NetWeaver Enterprise Portal processes attacker-controlled data supplied via a URL parameter and reflects it back into a server-generated HTML response without adequate output encoding or input neutralization. Because the reflected content is rendered by the browser as part of the portal's web page, an attacker can cause arbitrary client-side script execution in the security context of the portal's origin.

The core mechanism is classic reflected XSS:

1. A URL parameter accepted by the portal is not sanitized/escaped when written into the response body.
2. An attacker crafts a URL carrying script content in that parameter.
3. When the victim visits the crafted URL, the server reflects the payload and the browser executes it.

The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N describes the following characteristics:

• AV:N — exploitable over the network.
• AC:L — no special conditions beyond a crafted request.
• PR:N — no authentication required to deliver the malicious request.
• UI:R — the victim must take an action (visit the crafted URL / interact with the link).
• S:C — Scope is Changed; the vulnerable component and the impacted component differ, consistent with browser-side impact arising from server-reflected content.
• C:L / I:L / A:N — low confidentiality and integrity impact; no availability impact.

No public proof-of-concept, Nuclei template, or exploit code is known for this CVE, and no affected version data is present in the source record. The exact URL parameter name, endpoint path, and any application file/function involved are not specified in the available description and are therefore not asserted here. Detection and mitigation must be approached at the vulnerability-class level unless vendor-released technical detail becomes available.

Notably, the affected portal endpoints are network-exposed and, per the CVSS vector, the injection can be delivered without authentication. The requirement for user interaction (UI:R) means exploitation depends on luring a target user to a crafted URL.

Exploitation Scenarios

No public PoC available; the attack chain below is inferred from the vulnerability class (reflected XSS) and the NVD description. Only vulnerability-class level detail is asserted; no parameter names, endpoints, or function names are fabricated.

1. Reconnaissance / target identification

• Identify internet-facing or internal SAP NetWeaver Enterprise Portal deployments. Attackers commonly fingerprint portals by page titles, default portal paths, and the SAP-specific favicon.
• Determine which URL parameters are reflected into responses, using manual probing or automated parameter reflection testing (e.g., submitting benign markers and observing them echoed in the response body).

2. Triggering the flaw

• Craft a URL that places a script payload into a URL parameter known to be reflected by the portal.
• The request is delivered without authentication (PR:N). The payload is reflected by the server into the HTML response without proper encoding (CWE-79).

3. Payload / execution

• The attacker delivers the crafted URL to a user (UI:R), e.g., via phishing email, chat, or a link hosted on an attacker-controlled site.
• When the victim opens the URL, the browser renders the response and executes the injected script within the portal's origin. Scope is Changed (S:C) because the impact lands on the user's browser session rather than the server itself.

4. Post-exploitation impact

• Theft of session information (confidentiality impact, C:L), consistent with reading session tokens or data accessible in the victim's browser context.
• Manipulation of portal content (integrity impact, I:L), e.g., altering what the victim sees in the portal.
• Redirection of the user to attacker-controlled destinations.
• No availability impact (A:N) is expected based on the vulnerability description.

Because UI:R applies, mass exploitation is constrained by the need to induce user clicks. A successful attack can nonetheless escalate if the compromised session carries privileged portal capabilities.

Impact Assessment

Business impact centers on the SAP NetWeaver Enterprise Portal, a central access point for SAP business content and applications in many enterprises. A reflected XSS in this surface can be used for:

• Session hijacking / session information theft in the portal context (C:L).
• Content spoofing or manipulation of portal content seen by users (I:L).
• User redirection, which can support credential phishing or malware delivery.
• Chaining: a stolen portal session could be leveraged to access downstream content, raising real-world blast radius beyond the numeric C:L/I:L subscores.

Affected systems: SAP NetWeaver Enterprise Portal deployments. No affected version range is available in the provided data, so scope cannot be enumerated by version.

CVSS subscores (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N):

• Exploitability: Network, Low complexity, No privileges, User interaction required.
• Scope: Changed.
• Impact: Low confidentiality, Low integrity, None availability.
• Base score: 6.1 (Medium).

EPSS: Not yet scored by FIRST.org; no EPSS value is asserted. CISA KEV: NO. Patch confidence: 0/4 (UNPATCHED). No known in-the-wild exploitation is documented in the provided evidence.

Detection Guidance

Sigma Rule

Reflected XSS is best detected at the web-application layer (WAF/HTTP logs). The rule below detects common script-tag / event-handler payload patterns in inbound HTTP request fields, which is the request side of a reflected XSS attempt against any portal endpoint.

title: Possible Reflected XSS Attempt via HTTP Request Parameters (SAP NetWeaver Enterprise Portal)
id: 6f2b5a91-2c3e-4d17-9c88-1b0e2f7a4d33
status: experimental
description: Detects common cross-site scripting payload patterns in HTTP request URIs and parameters, indicative of reflected XSS attempts against web applications such as SAP NetWeaver Enterprise Portal (CVE-2026-89117 class).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-89117
author: Threat Intelligence
date: 2026/06/15
logsource:
  category: webserver
detection:
  selection_uri:
    cs-uri-query|contains:
      - '<script'
      - '%3Cscript'
      - 'javascript:'
      - 'onerror='
      - 'onload='
      - '<svg'
      - '%3Csvg'
      - 'alert('
      - 'document.cookie'
  condition: selection_uri
falsepositives:
  - Legitimate application parameters that contain HTML-like content
  - Security scanners and fuzzing tools
level: medium
tags:
  - attack.t1189
  - cwe.79

YARA Rule

No malicious file artifact is associated with this CVE (it is a network-delivered reflected XSS). The YARA rule below targets files/logs that contain reflected-XSS payload patterns for hunting cached HTTP captures or application logs.

rule CVE_2026_89117_Reflected_XSS_Payload
{
    meta:
        description = "Detects common reflected XSS payload patterns associated with CVE-2026-89117 class web requests"
        author = "Threat Intelligence"
        date = "2026-06-15"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-89117"
        cwe = "CWE-79"

    strings:
        $xss1 = "<script" ascii nocase
        $xss2 = "javascript:" ascii nocase
        $xss3 = "onerror=" ascii nocase
        $xss4 = "onload=" ascii nocase
        $xss5 = "document.cookie" ascii nocase
        $xss6 = "%3Cscript%3E" ascii nocase
        $xss7 = "<svg/onload" ascii nocase
        $xss8 = "alert(" ascii nocase

    condition:
        any of them
}

Suricata IDS Rule

Detects script payload patterns in HTTP request URIs, the delivery vector for reflected XSS.

alert http any any -> any any (msg:"CVE-2026-89117 Possible Reflected XSS in HTTP Request URI (script payload)"; flow:established,to_server; http.uri; content:"<script"; nocase; sid:202689117; rev:1; reference:cve,2026-89117; classtype:web-application-attack; metadata:attack_target Web_Server, created_at 2026_06_15, cve CVE_2026_89117;)

alert http any any -> any any (msg:"CVE-2026-89117 Possible Reflected XSS Event Handler Payload (onerror/onload)"; flow:established,to_server; http.uri; pcre:"/on(error|load|mouseover|focus)\s*=/i"; sid:202689118; rev:1; reference:cve,2026-89117; classtype:web-application-attack; metadata:attack_target Web_Server, created_at 2026_06_15, cve CVE_2026_89117;)

Elastic Detection

EQL query over web access logs (e.g., Filebeat/Elastic Agent http logs) for script payload patterns in URL/query fields.

any where
  (url.query : ("*<script*" or "*%3Cscript*" or "*javascript:*" or "*onerror=*" or "*onload=*" or "*<svg*" or "*document.cookie*"))
  or
  (url.full : ("*<script*" or "*%3Cscript*" or "*javascript:*" or "*onerror=*" or "*onload=*"))

Analyst note: correlate field names with your ingestion pipeline (for example url.query, url.full, or a custom request-parameter field). Broad matches may indicate scanners; treat high-volume or targeted matches as suspicious.

Splunk SPL Query

Search web/proxy logs for inbound requests carrying XSS payload patterns. Adjust index/sourcename to your environment.

index=web OR index=proxy
| eval req = lower(coalesce(uri, url, cs_uri_stem) . " " . coalesce(uri_query, cs_uri_query, url_query, ""))
| where match(req, "<script|%3cscript|javascript:|onerror=|onload=|%3csvg|document\.cookie|alert\(")
| stats count min(_time) as first_seen max(_time) as last_seen values(src_ip) as source_ips by req, host
| sort - count

Optional: add a threshold and lookup of known-good scanners to reduce noise:

| where count > 3 AND NOT cidrmatch("10.0.0.0/8", source_ips)

Wazuh OSSEC Rule

Wazuh rule to alert on XSS payload patterns in web server access logs (paired with a web-log decoder such as web-accesslog).

<group name="web,appsec,cve-2026-89117,">
  <rule id="2026891" level="10">
    <if_sid>31100</if_sid>
    <match>script|%3Cscript|javascript:|onerror=|onload=|%3Csvg|document\.cookie|alert\(</match>
    <description>CVE-2026-89117: Possible reflected XSS payload detected in web request (script/event handler pattern)</description>
    <mitre>
      <id>T1189</id>
    </mitre>
    <group>attack,cwe_79,</group>
  </rule>
</group>

Ensure the parent SID (31100 is the standard web-accesslog decoder chain) matches your Wazuh installation; adjust if your environment uses a different web-log decoder.

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix, workaround, affected version list, or OSV package data was provided. The guidance below is therefore standard XSS mitigation for the vulnerability class, not a confirmed vendor remediation.

1. Immediate mitigations

• Deploy WAF rules to block script-tag and event-handler payload patterns in request parameters (see Suricata/Sigma rules above). WAFs are compensating controls, not fixes.
• Restrict network exposure of SAP NetWeaver Enterprise Portal; do not expose portal endpoints directly to the internet where avoidable; require VPN or zero-trust access for administrative/portal surfaces.
• Lower the value of XSS by protecting session cookies: enforce HttpOnly and Secure cookie attributes, and SameSite=Strict/Lax, on portal session cookies. HttpOnly prevents script access to cookies, directly reducing the C:L session-theft vector.
• Deploy a strict Content-Security-Policy (CSP) that disallows inline script and restricts script sources; this can neutralize reflected script execution in supporting browsers.
• Harden browsers/email gateways: strip or flag URLs containing script payload patterns; user awareness for phishing links (UI:R is required for exploitation).

2. Patch / upgrade steps

• No patch reference is available from tracked sources as of this writing. Monitor SAP Security Notes and the SAP Support Portal for a note covering NetWeaver Enterprise Portal reflected XSS, and apply the corresponding SAP Security Note as soon as it is released.
• Subscribe to SAP Security Patch Day advisories and the vendor's CVE communications to obtain the affected version range and fixed release.
• When a fix lands, inventory NetWeaver Enterprise Portal instances, determine exposed versions, and schedule emergency change windows for internet-facing and externally reachable systems first.

3. Long-term hardening

• Adopt secure coding practices for output encoding (context-aware HTML/attribute/JS/URL encoding) across the portal.
• Enforce Content-Security-Policy and other security headers (X-Content-Type-Options, Referrer-Policy) at the edge/reverse proxy.
• Implement regular authenticated and unauthenticated web application scanning focused on reflection points and XSS.
• Maintain an SBOM/asset inventory for SAP components to shorten future response windows.
• Segment SAP application tiers so a client-side compromise cannot easily pivot into backend systems.

References

• NVD — CVE-2026-89117: https://nvd.nist.gov/vuln/detail/CVE-2026-89117
• CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'): https://cwe.mitre.org/data/definitions/79.html
• MITRE ATT&CK T1189 — Drive-by Compromise: https://attack.mitre.org/techniques/T1189/
• OWASP — Cross Site Scripting (XSS) Prevention Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html
• SAP Security Notes / SAP Support Portal (monitor for the vendor advisory and fixed version; not yet published per tracked data): https://support.sap.com/en/my-support/knowledge-base/security-notes-news.html

Threat actor / exploit-in-the-wild evidence: none documented in the provided data. CISA KEV status: NO. No public PoC, Nuclei template, or exploit code is known for this CVE as of this report.