How severe is CVE-2026-31950?

CVE-2026-31950 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-31950 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-31950?

CVE-2026-31950 primarily affects Librechat. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-31950?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-31950 have an EU (EUVD) identifier?

Yes. CVE-2026-31950 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16767.

When was CVE-2026-31950 published?

CVE-2026-31950 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-31950

CVE-2026-31950 is a medium-severity vulnerability in Librechat with a CVSS 3.x base score of 5.3. 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-639.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16767
Weakness: CWE-639
Affected product: Librechat
Published: 2026-03-27
Last modified: 2026-06-17

Description

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint `/api/agents/chat/stream/:streamId` does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and read another user's real-time chat content, including messages, AI responses, and tool invocations. Version 0.8.2 patches the issue.

Frequently asked questions

What is CVE-2026-31950?: LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint `/api/agents/chat/stream/:streamId` does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and read another user's real-time chat content, including messages, AI responses, and tool invocations. Version 0.8.2 patches the issue.
How severe is CVE-2026-31950?: CVE-2026-31950 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-31950 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-31950?: CVE-2026-31950 primarily affects Librechat. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-31950?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-31950 have an EU (EUVD) identifier?: Yes. CVE-2026-31950 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16767.
When was CVE-2026-31950 published?: CVE-2026-31950 was published on 2026-03-27 and last updated on 2026-06-17.

References

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-f6rf-vm44-wh5g

Affected products (2)

cpe:2.3:a:librechat:librechat:0.8.2:rc2:*:*:*:*:*:*
cpe:2.3:a:librechat:librechat:0.8.2:rc3:*:*:*:*:*:*

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