How severe is CVE-2026-4959?

CVE-2026-4959 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-4959 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4959?

CVE-2026-4959 affects Openbmb Xagent. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-4959?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-4959 have an EU (EUVD) identifier?

Yes. CVE-2026-4959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16692.

When was CVE-2026-4959 published?

CVE-2026-4959 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-4959

CVE-2026-4959 is a high-severity vulnerability in Openbmb Xagent with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v2: 7.5
CVSS v4: 5.5
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16692
Weakness: CWE-287
Affected product: Openbmb Xagent
Published: 2026-03-27
Last modified: 2026-06-17

Description

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 respond in any way.

Frequently asked questions

What is CVE-2026-4959?: 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 respond in any way.
How severe is CVE-2026-4959?: CVE-2026-4959 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-4959 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4959?: CVE-2026-4959 affects Openbmb Xagent. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-4959?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-4959 have an EU (EUVD) identifier?: Yes. CVE-2026-4959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16692.
When was CVE-2026-4959 published?: CVE-2026-4959 was published on 2026-03-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:openbmb:xagent:1.0.0:*:*:*:*:*:*:*

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CVE-2025-6281 — Medium (CVSS 5.5): A vulnerability has been found in OpenBMB XAgent up to 1.0.0 and classified as critical. Affected by this vulnerability…
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