CVE-2026-78550

Executive Summary

CVE-2026-78550 is an authenticated remote code execution vulnerability in the Okta Access Gateway management console, caused by unsanitized user-supplied input being passed to eval() during an administrator SSH session (CWE-95, Improper Neutralization of Directives in Dynamically Evaluated Code). Exploitation requires valid administrative credentials and SSH access to the management plane, significantly constraining the attack surface to privileged insiders, compromised admin accounts, or attackers who have already achieved administrative foothold. Successful exploitation yields code execution with the privileges of the management console — a high-integrity, high-confidentiality, high-availability impact on the affected appliance.

Technical Analysis

The flaw resides in the management console component of Okta Access Gateway. As described by NVD, the console "passes user-supplied input to eval() without sanitization during an authenticated administrator SSH session." The eval() construct interprets its argument as executable code within the runtime context of the management console. Because no sanitization occurs, any input reaching that sink is interpreted as code rather than treated as inert data.

CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code, colloquially "Eval Injection") is the assigned class. The defining characteristic is the direct routing of attacker-controlled input into a dynamic evaluation sink. Unlike command injection (CWE-78), which abuses a shell intermediary, CWE-95 abuses the host language's own interpreter, meaning the injected logic executes with the same privileges and within the same process context as the management console itself. This eliminates any shell-quoting escape hatch and gives the attacker full programmatic reach within the runtime.

The attack surface is the management console as exposed over SSH. The vulnerable interaction is explicitly described as occurring "during an authenticated administrator SSH session," indicating the console presents an administrative interface (menu, command handler, or prompt) via SSH, and at least one input path from that session flows into eval() unmodified. The precise parameter name, handler function, or input verb is not disclosed in the NVD description, and no vendor advisory (CNA Title empty) or patch source is available to reconstruct the exact call chain. Per strict accuracy constraints, the report does not speculate on specific function names, API paths, or parameters.

Key CVSS interpretation: AV:N (network reachable SSH), AC:H (high attack complexity — likely reflecting the need for a valid admin session and possibly a narrow trigger condition), PR:H (administrator privileges required), UI:N (no victim user interaction beyond the attacker's own session), and C:H/I:H/A:H (full triad impact). The composite 6.6 base score reflects that while impact is severe, the privileged preconditions materially reduce exploitability relative to an unauthenticated RCE.

Public PoC status is recorded as "Public," but no exploit code repository is tracked and no Nuclei template exists. The public PoC designation should be treated as indicating that exploitation knowledge is circulating, not that weaponized tooling is confirmed in the tracked dataset.

Exploitation Scenarios

The following is inferred strictly from the vulnerability class and the single-sentence NVD description. No public exploit code is available in tracked sources; the attack chain below is derived from CWE-95 mechanics.

1) Reconnaissance and target identification. An adversary first locates an Okta Access Gateway management console exposed on the network. Because the vulnerable path is the management console's SSH service, reconnaissance focuses on identifying reachable SSH endpoints associated with the appliance (banner grabbing, certificate subject inspection, Shodan/Censys enumeration of Okta Access Gateway assets). A prerequisite for the next stage is acquisition of valid administrator credentials — via phishing, credential reuse, theft from a prior compromise, or an insider role.

2) Triggering the flaw. The attacker authenticates to the management console over SSH as an administrator. Within that authenticated session, they reach the input surface that the console routes into eval(). Because the input is not sanitized, the content the attacker supplies is delivered verbatim to the interpreter instead of being treated as plain data. The attacker does not need to chain a memory-safety bug or bypass a sandbox — the console itself performs the evaluation.

3) Payload/execution. At the vulnerability-class level, the injected content is language-level code that the runtime evaluates directly. This is distinct from shell-command injection: the payload is interpreted by the management console's own execution environment, granting the same privileges the console holds. Precise payload construction depends on the console's host language and runtime, which are not disclosed; no specific syntax, function call, or gadget is asserted here.

4) Post-exploitation impact. Code executes "with the privileges of the management console." In a federated-access appliance, the management console governs identity-brokering configuration, certificates, and trust relationships, so console-privileged execution plausibly exposes sensitive configuration and credential material and permits persistent modification of the access-control behavior the appliance enforces. Post-exploitation activity would be aimed at privilege preservation within the console context and pivoting into the broader Okta-integrated environment — though the exact capabilities are bounded by the console process's own permissions, which are not enumerated in available sources.

Because exploitation demands administrator-level SSH access, this is best characterized as a privilege-escalation-to-execution vector for an already-privileged actor rather than an external pre-auth entry point.

Impact Assessment

Business impact centers on the identity trust plane. Okta Access Gateway sits in front of protected applications and brokers authentication, so code execution on its management console is high-leverage: compromise can disrupt authentication flows (Availability), expose configuration and credential material (Confidentiality), and allow tampering with access-control decisions (Integrity). The CVSS vector assigns C:H/I:H/A:H — full impact across the triad — consistent with console-level compromise of a security-critical appliance.

Blast radius is bounded by the administrator precondition. The PR:H/AC:H combination means an attacker must already possess admin credentials and reach the SSH management plane; this suppresses mass-exploitation potential (reflected by the 6.6 base score and a low EPSS of 0.00491, ~39.8th percentile). However, EPSS measures near-term exploitation likelihood across the CVE corpus, not severity — a low EPSS with high impact still warrants prioritized patching for any organization running Okta Access Gateway with network-exposed SSH management access.

Affected systems: Okta Access Gateway appliances with reachable management consoles. No OSV package data or version range is tracked, so precise fleet scoping must be established directly against the vendor's advisory and asset inventory. CISA KEV listing: NO — no confirmed in-the-wild exploitation at time of writing.

Detection Guidance

Sigma Rule

title: Suspicious Administrative SSH Session to Okta Access Gateway Management Console
id: 8f2c1e7a-4b6d-4c2e-9a10-3d5e6f7a8b9c
status: experimental
description: Detects SSH administrative sessions against Okta Access Gateway management console, a precondition for CVE-2026-78550 exploitation.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-78550
author: valtersit.com
date: 2026/01/01
logsource:
  product: linux
  service: sshd
detection:
  selection_accept:
    message|contains: 'Accepted'
  selection_agw_user:
    message|contains:
      - 'admin'
      - 'okta'
      - 'agw'
  condition: selection_accept and selection_agw_user
falsepositives:
  - Legitimate administrator maintenance sessions
level: medium
tags:
  - attack.t1059
  - cve.2026.78550

YARA Rule

rule CVE_2026_78550_Okta_Access_Gateway_Eval_Injection
{
    meta:
        description = "Flags potential eval-injection payload indicators in Okta Access Gateway console logs/artifacts (CVE-2026-78550)"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-78550"
        cve = "CVE-2026-78550"
        date = "2026-01-01"
    strings:
        $agw = "Access Gateway" ascii nocase
        $ev1 = "eval(" ascii nocase
        $ev2 = "Runtime.getRuntime" ascii
        $ev3 = "ProcessBuilder" ascii
        $ev4 = "subprocess" ascii nocase
        $ssh_admin = "administrator SSH session" ascii nocase
    condition:
        $agw and (1 of ($ev*))
}

Suricata IDS Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 22 (msg:"CVE-2026-78550 Okta Access Gateway management console SSH session possibly exploited - eval injection input"; flow:to_server,established; content:"eval"; nocase; threshold:type threshold, track by_src, count 5, seconds 60; sid:2026785501; rev:1; reference:cve,2026-78550; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-78550; classification:attempted-admin;)

Elastic Detection

sequence by process.entity_id with maxspan=5m
  [process where event.type == "start" and process.name in ("sshd", "sshd-session")]
  [process where event.category == "process" and
     process.command_line : ("*eval*" or "*Runtime.getRuntime*" or "*ProcessBuilder*")]

Splunk SPL Query

index=linux sourcetype=linux_secure OR sourcetype=syslog
| search ("Access Gateway" OR okta_access_gateway)
| search ("Accepted" AND ("admin" OR "administrator"))
| stats count min(_time) as first_seen max(_time) as last_seen values(src_ip) as source_ips by user host
| where count > 0

Wazuh OSSEC Rule

<group name="okta_access_gateway,cve-2026-78550,">
  <rule id="100850" level="10">
    <decoded_as>sshd</decoded_as>
    <match>Accepted</match>
    <regex>admin|administrator</regex>
    <description>CVE-2026-78550: Admin SSH session to Okta Access Gateway management console - potential eval-injection precondition</description>
    <mitre>
      <id>T1059</id>
    </mitre>
    <group>cve_2026_78550,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED. No vendor fix, workaround, or affected-version data is available from any tracked source.

1. Immediate mitigations. Restrict SSH access to the management console to a hardened bastion or dedicated management VLAN, enforced by least-privilege firewall rules and network ACLs (never expose the console to the internet). Enforce strong multi-factor authentication and segregation of administrator accounts for the console. Monitor administrative SSH sessions for anomalous input and terminate unrecognized sessions. Rotate administrator credentials and any secrets stored in or referenced by the console configuration.

2. Patch/upgrade steps. No patch reference exists at this time. Track the Okta Access Gateway security advisory channel and apply the vendor fix immediately once published. Because no affected-version range is tracked, maintain an accurate asset inventory of Okta Access Gateway deployments now, so patching can be executed as soon as vendor guidance arrives. Validate signatures/hashes of any update against the vendor's published source before deployment.

3. Long-term hardening. Remove or disable any dynamic code-evaluation behavior in the console where possible; remediate the CWE-95 pattern at the source (never route user input to eval(); use allow-listed parsing). Apply the principle of least privilege to the management-console process so that post-exploitation code executes with the minimum feasible rights. Maintain centralized logging of all console/admin sessions with alerting on the detection rules above. Given the identity-plane sensitivity, subscribe to Okta advisories and integrate CVE monitoring with a patch SLA for security-critical appliances.

References

• NVD — CVE-2026-78550: https://nvd.nist.gov/vuln/detail/CVE-2026-78550
• CWE-95 — Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection'): https://cwe.mitre.org/data/definitions/95.html
• Okta Security Advisories (vendor advisory channel — monitor for Access Gateway fix): https://trust.okta.com/security-advisories/
• MITRE ATT&CK T1059 — Command and Scripting Interpreter: https://attack.mitre.org/techniques/T1059/
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-78550 not listed as of reporting): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Note: No threat actor campaign or confirmed exploit-in-the-wild evidence is associated with CVE-2026-78550 in tracked sources. Public PoC status is recorded, but no public exploit code or Nuclei template is available in the dataset. EPSS is 0.00491 (39.8th percentile).