CVE-2026-22813Public exploitNetwork attack vector

Command execution via unsanitized Markdown response HTML

Published Jan 12, 2026 · Updated Jan 12, 2026

Cross-site scripting in Anomaly OpenCode before 1.1.10 allows remote attackers to execute local commands through a crafted link. The web UI's Markdown renderer inserts attacker-controlled LLM response HTML into the DOM without sanitization or a CSP, while the url parameter loads sessions from an attacker-controlled server. Execution requires a local OpenCode server and a user to open the link; injected JavaScript then calls same-origin pty endpoints to spawn processes with the user's privileges.

CVSS severity9.4
Critical
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Anomaly OpenCode before 1.1.10 allows remote attackers to execute local commands through a crafted link. The web UI's Markdown renderer inserts attacker-controlled LLM response HTML into the DOM without sanitization or a CSP, while the url parameter loads sessions from an attacker-controlled server. Execution requires a local OpenCode server and a user to open the link; injected JavaScript then calls same-origin pty endpoints to spawn processes with the user's privileges.

The record

CVE
CVE-2026-22813
Published
Jan 12, 2026
Updated
Jan 12, 2026
Vendor
Anomaly
Product
OpenCode
Classifications
CWE-79, T1204.001, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.1.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Anomaly · OpenCodeversion=< 1.1.10

Published CVSS scores

9.4GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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