CVE-2026-75697

Executive Summary

CVE-2026-75697 is a stored Cross-Site Scripting (XSS) vulnerability affecting Adobe Connect, rated CVSS 9.3 (Critical). An attacker can inject malicious JavaScript into vulnerable form fields; the script is persisted server-side and executes in the browser of any victim who views the affected page. Successful exploitation enables elevated access or control over the victim's account or session, with a changed scope (S:C), meaning the compromise can extend beyond the vulnerable component to other security authorities.

Technical Analysis

The vulnerability class is CWE-79 (Improper Neutralization of Input During Web Page Generation), specifically the stored (persistent) subtype. Unlike reflected XSS, in which the payload must be delivered through a crafted link in the same request/response cycle, a stored XSS flaw requires that attacker-supplied input be persisted by the application (database, cache, or other server-side store) and later rendered into a page without adequate output encoding or sanitization. The NVD description states the injection point is "vulnerable form fields" within Adobe Connect, and that "malicious JavaScript may be executed in a victim's browser when they browse to the page containing the vulnerable field."

The CVSS vector components are analytically significant:

• AV:N (Network) — the attack is delivered over the network; no local access or adjacency is required.
• AC:L (Low) — no special conditions beyond standard reachability are required. The supplied data does not describe race conditions, memory layout constraints, or unusual preconditions.
• PR:N (None) — the attacker does not require an authenticated account or any privilege on the target to deliver the payload. This is consistent with stored XSS in a form or field that can be populated pre-authentication or by an unprivileged user (for example, a meeting registration field, public-facing form, or profile attribute), though the exact Adobe Connect form is not specified in the supplied data.
• UI:R (Required) — a victim must browse to the page containing the vulnerable, already-poisoned field. The attacker does not need to trick the victim into a specific click on a malicious link (as would be typical of reflected XSS); the victim simply needs to load a legitimate, trusted page that happens to contain the stored payload.
• S:C (Changed) — the exploited vulnerability's impact crosses a trust boundary. The vulnerable component is the field/page rendering; the impacted component includes the victim's session and account context. This is why the score is elevated: a compromise of the rendering context can translate into control over a separate security authority (the user's authenticated session).
• C:H / I:H — high confidentiality and integrity impact; a script executing in the origin of Adobe Connect can read page content and session-accessible data and can perform state-changing actions as the victim.
• A:N — no availability impact is claimed.

Notable operational characteristics: because the payload is stored, it persists until removed, executes for every user who visits the affected field/page, and does not require the attacker to be present at exploitation time. The attack surface is the set of forms/fields in the product that accept and re-render user input without proper contextual output encoding. Insufficient technical detail is available in the supplied intelligence to identify the specific form, parameter, encoding failure, or vulnerable component version.

Exploitation Scenarios

No public PoC, exploit code, or Nuclei template is available; the attack chain below is inferred from the stored XSS vulnerability class and the NVD description only. No specific function names, parameters, or endpoints are asserted because none are provided.

1. Reconnaissance / target identification. The attacker identifies an internet-reachable or internally reachable Adobe Connect deployment. Enumeration focuses on user-populated forms and displayed fields — anything a user can submit that is later rendered to other users or back to the same user. Given PR:N, the attacker prioritizes fields writable with no or minimal privilege.

2. Triggering the flaw class. The attacker submits input into a vulnerable form field that the application persists without neutralizing HTML/JavaScript metacharacters. Because the description specifies a stored XSS, the payload must survive storage and be emitted later during page generation without proper output encoding. At the vulnerability-class level, the mechanism is: unsanitized user input → server-side persistence → unsafely rendered into a subsequent HTML response.

3. Payload / execution method. A JavaScript payload is injected into the field. When any user browses to the page containing the vulnerable field, the payload is delivered as part of the trusted Adobe Connect page and executes in that user's browser under the application's origin. No specific encoding or filter-bypass technique is asserted here, as the supplied data does not describe the sanitization implementation.

4. Post-exploitation impact. Execution in the victim's browser context allows the attacker to act with the victim's session/account authority — read data accessible to the page, perform actions on the victim's behalf, or otherwise gain "elevated access or control over the victim's account or session," as stated in the NVD description. The S:C rating indicates the compromise is not contained to the rendering component and can affect the broader account/session security context. The supplied data does not describe secondary lateral-movement or persistence mechanisms.

Impact Assessment

• Confidentiality (High): script in the application origin can access data rendered to and reachable by the victim's session.
• Integrity (High): the attacker can cause state changes within the victim's account/session.
• Availability (None per vector): no denial-of-service impact is scored.
• Scope Changed: the vulnerability exists in a page/field component but its consequences extend to the victim's account or session security authority — a cross-boundary impact that justifies the 9.3 rating.

Blast radius is a function of who views the poisoned field. If the field is displayed to administrative or high-privileged users, the effective compromise level rises substantially; stored XSS is frequently chained to administrative session theft or to persistent malware-like behavior against all visitors. Because the payload is persistent, a single successful injection can affect an unbounded number of users over time until remediated — a materially larger blast radius than a reflected XSS of equivalent CVSS. Affected systems are Adobe Connect deployments; no version range is available from the supplied intelligence, so all deployments should be treated as potentially affected pending vendor confirmation. CISA KEV status is NO, and there is no reported exploit-in-the-wild evidence in the supplied data.

Detection Guidance

Sigma Rule

title: Stored XSS Payload Submitted to Adobe Connect Form Field
id: 7b2f4c1a-9e3d-4a8b-b6c1-2f5d8e0a9c47
status: experimental
description: Detects submission of HTML/JavaScript metacharacters in requests to Adobe Connect form endpoints, consistent with stored XSS injection (CVE-2026-75697).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-75697
author: valtersit.com Threat Intelligence
date: 2026-01-01
logsource:
  category: webserver
  product: apache
detection:
  selection_method:
    cs-method:
      - POST
      - PUT
  selection_payload:
    - 'script>'
    - 'onerror='
    - 'onload='
    - 'javascript:'
    - '<svg'
    - '<img'
    - 'document.cookie'
  condition: selection_method and selection_payload
falsepositives:
  - Legitimate rich-text content containing markup
  - Security scanners and fuzzing tools
level: high
tags:
  - attack.t1059.007
  - cwe.cwe-79

YARA Rule

rule CVE_2026_75697_Adobe_Connect_Stored_XSS
{
    meta:
        description = "Detects JavaScript/HTML XSS payload artifacts associated with CVE-2026-75697 (Adobe Connect stored XSS)"
        author = "valtersit.com Threat Intelligence"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-75697"
        date = "2026-01-01"
        severity = "critical"

    strings:
        $xss1 = "<script" ascii nocase wide
        $xss2 = "</script>" ascii nocase wide
        $xss3 = "javascript:" ascii nocase wide
        $xss4 = "onerror=" ascii nocase wide
        $xss5 = "onload=" ascii nocase wide
        $xss6 = "document.cookie" ascii nocase wide
        $xss7 = "svg/onload" ascii nocase wide
        $ctx1 = "adobe" ascii nocase
        $ctx2 = "connect" ascii nocase

    condition:
        (2 of ($xss*)) and (any of ($ctx*))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-75697 Possible Adobe Connect Stored XSS Injection Attempt"; flow:established,to_server; http.method; content:"POST"; http.request_body; content:"script"; nocase; http.request_body; content:"onerror="; nocase; http.request_body; content:"<" ; nocase; threshold: type both, track by_src, count 5, seconds 60; classtype:web-application-attack; reference:cve,2026-75697; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-75697; sid:202675697; rev:1;)

Elastic Detection

sequence by source.ip, user.name with maxspan=5m
  [ network where http.request.method == "POST" and
      http.request.body.content : ("<script" or "onerror=" or "javascript:" or "document.cookie") ]
  [ network where http.response.status_code == 200 ]

Splunk SPL Query

index=web sourcetype=access_combined OR sourcetype=adobe:connect
| eval body=coalesce(form_data, request_body, post_data, "")
| where match(body, "(?i)(<script|onerror\s*=|onload\s*=|javascript:|<svg|document\.cookie)")
| stats count min(_time) as first_seen max(_time) as last_seen values(uri_path) as paths by src_ip, user
| where count >= 1
| convert ctime(first_seen) ctime(last_seen)
| sort - count

Wazuh OSSEC Rule

<group name="web,appsec,adobe_connect,">
  <rule id="202697" level="12">
    <if_sid>31100,31101,31103,31106</if_sid>
    <regex type="pcre2">(?i)(%3Cscript|<script|onerror\s*=|onload\s*=|javascript%3A|javascript:|document\.cookie)</regex>
    <description>CVE-2026-75697: Possible Adobe Connect stored XSS injection attempt detected in HTTP request.</description>
    <mitre>
      <id>T1059.007</id>
    </mitre>
    <group>cve_2026_75697,xss,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED. No patch or version information is available from any tracked source. No vendor fix or workaround is documented in the supplied intelligence.

1. Immediate mitigations (compensating controls only — none are vendor-supplied):

   • Deploy a web application firewall (WAF) with virtual patching tuned to block HTML/JavaScript metacharacters and event-handler attributes in form submissions to Adobe Connect endpoints. Treat WAF coverage as a mitigation layer, not a fix.
   • Enforce strict Content Security Policy (CSP) headers on all Adobe Connect pages to reduce inline script execution capability where the application architecture permits.
   • Restrict network exposure of Adobe Connect to trusted networks, VPN, or zero-trust proxies to reduce attacker reach (the vector is AV:N).
   • Enforce short session lifetimes and re-authentication for privileged accounts to limit the window of session/session-token abuse after a successful XSS.
   • Monitor for and manually purge any stored content in user-populated fields pending an official fix.

2. Patch/upgrade steps:

   • No patch is available per available intelligence. Monitor Adobe's security advisories and the Adobe Connect release notes channel for an official fix, and apply it immediately upon release.
   • Once a fix version is published, inventory all Adobe Connect deployments and upgrade. Because no affected-version range is known, treat all versions as potentially affected until Adobe publishes a definitive matrix.

3. Long-term hardening:

   • Enforce context-aware output encoding and input validation for all user-populated fields as a platform requirement, and adopt a secure SDLC that includes XSS testing in CI/CD.
   • Adopt a Content Security Policy with nonce- or hash-based script allowlisting as a default control for the product.
   • Deploy authenticated web-application monitoring with alerting on injection-pattern submissions and on anomalous in-session activity.
   • Track CVE-2026-75697 and the associated CWE-79 advisories, and subscribe to Adobe, CISA, and NVD feeds for patch availability. There is no CISA KEV listing and no reported active exploitation in the supplied data, but the high CVSS and PR:N/UI:R profile make it a priority for pre-patch monitoring.

References

• NVD — CVE-2026-75697: https://nvd.nist.gov/vuln/detail/CVE-2026-75697
• CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'): https://cwe.mitre.org/data/definitions/79.html
• Adobe Security Advisories: https://helpx.adobe.com/security.html
• MITRE ATT&CK T1059.007 — Command and Scripting Interpreter: JavaScript: https://attack.mitre.org/techniques/T1059/007/
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-75697 not listed as of available intelligence): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

No threat actor campaigns or exploit-in-the-wild evidence were identified in the supplied intelligence for CVE-2026-75697.