CVE-2026-62674: Omnigent: Shared Agent Bundle Overwrite Leads to Authenticated Runner RCE

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.5%, percentile 42: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 42% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes omnigent (PyPI) < 0.3.0, fixed in 0.3.0. Check your lockfile, including transitive dependencies.

What it is

Omnigent is an open-source AI agent framework and meta-harness for orchestrating coding agents. Prior to 0.3.0, PUT /sessions/{sessionid}/agent checks LEVELEDIT permission for a session but does not reject a bound shared or template agent whose agent.sessionid is None. An authenticated user with edit access to a session can replace that shared agent bundle through omnigent/server/routes/sessions.py, add a stdio MCP server, and cause later sessions that use the shared agent to launch an attacker-controlled command through omnigent/tools/mcp.py. The command executes with the Omnigent runner process permissions and can expose files, credentials, workspace data, internal services, and runner availability. This issue is fixed in version 0.3.0.

From the GitHub advisory

Summary

An authenticated user with edit access to their own session can overwrite a shared/template agent by uploading a full agent bundle through PUT /sessions/{sessionid}/agent.

Shared/template agents are shown as not MCP-editable, but this upload path still accepts a replacement bundle. By adding a stdio MCP server to the shared agent, the attacker can cause future runner sessions using that shared agent to start an attacker-controlled command.

Details

The vulnerable endpoint is the full agent bundle upload route: PUT /sessions/{sessionid}/agent This route checks whether the caller can edit the session: LEVELEDIT session permission check But it does not check whether the bound agent is a shared/template agent. Shared/template agents have:

Weakness type: CWE-94.

Product: omnigent (PyPI) · Assigned by: GitHub_M · Published: 2026-08-21

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: required (a user must click/open something)
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.51% probability of exploitation activity in the next 30 days; percentile 42.

Timeline

• 2026-08-21 — CVE record published by GitHub_M
• 2026-08-25 — CVE record last updated
• 2026-09-02 — GitHub-reviewed advisory GHSA-jrrm-9hc7-2v3h published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-jrrm-9hc7-2v3h github.com
2. CVE.org record CVE-2026-62674 cve.org
3. NVD entry CVE-2026-62674 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical PyPI advisories · Today’s Security Digest