CVE-2026-4959: A vulnerability was found in OpenBMB XAgent 1.0.0

This week

HIGH 7.3REMOTEDOWNGRADE

CVE-2026-4959 is a high-severity flaw (CVSS 7.3) affecting xagent. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was found in OpenBMB XAgent 1.0.0. This impacts the function check_user of the file XAgentServer/application/websockets/share.py of the component ShareServer WebSocket Endpoint. Performing a manipulation of the argument interaction_id results in missing authentication. Remote exploitation of the attack is possible. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 61%)
CISA exploited list	No
Weakness	CWE-287, CWE-306
Published	2026-03-27
Last modified	2026-10-26

Publisher (CNA): VulDB · Vendor: openbmb

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-27 16:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

openbmb xagent DOWNGRADE

Affected: 1.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy xagent || rpm -q xagent || xagent --version

2. No fixed release: DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison xagent sudo apt install xagent=<VERSION_BEFORE_1.0.0> sudo apt-mark hold xagent

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list xagent sudo dnf downgrade xagent-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add xagent

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-4959?

xagent: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-4959 being exploited?

CVE-2026-4959 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-4959 affect?

CVE-2026-4959 affects xagent. Severity is high (CVSS 7.3). A vulnerability was found in OpenBMB XAgent 1.0.0. This impacts the function check_user of the file XAgentServer/application/websockets/share.py of the component ShareServer WebSocket Endpoint. Performing a manipulation of the argument inte

How urgent is CVE-2026-4959?

Priority 45/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-4958 LOW 3.1 DOWNGRADE A vulnerability has been found in OpenBMB XAgent 1.0.0
CVE-2026-4957 LOW 2.7 DOWNGRADE A flaw has been found in OpenBMB XAgent 1.0.0

References

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