Answer in brief
CVE-2026-54275 records a High severity (CVSS 7.5) vulnerability in aiohttp: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections. The current sources do not mark it as known exploited. The current feed maps aiohttp (pip), aiohttp (pypi). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps aiohttp (pip), aiohttp (pypi). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| aiohttppip | <=3.14.0 | 3.14.1 |
| aiohttppypi | >=0 <3.14.1 | 3.14.1 |
Published upstream
Jun 15, 2026
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
### Summary The `server_hostname` TLS SNI check can be bypassed when an existing connection is reused. ### Impact 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. ### Workaround Disable keep_alive if you need to change the `server_hostname` check between requests. ----- Patch: https://github.com/aio-libs/aiohttp/commit/0ca2b6c28a25726527a8b60f25960262a91ed0e0
Quoted source text, attributed separately from HOL analysis.