Is CVE-2026-54275 in the CISA KEV catalog?

No. CVE-2026-54275 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-54275?

CVE-2026-54275 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-54275?

CVE-2026-54275 has an EPSS score of 0.25% (17th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-54275

HIGH

7.5

CVSS v3

NVD

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the server_hostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check. This vulnerability is fixed in 3.14.1.

CWE-297

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.25%probability of exploitation in 30 days

17thpercentile

Low risk: more likely to be exploited than 17% of all known CVEs.

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-4m7w-qmgq-4wj5

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-26.