8.1

CVE-2026-84381: HTTPX2: Secure WebSocket traffic sent without TLS through SOCKS proxies

Awaiting analysis
AliasesGHSA-7mj9-2mp8-4m2pPYSEC-2026-3844PYSEC-2026-3845
Published 02-09-2026Last modified 05-09-2026

Vulnerability summary

CVE-2026-84381 is a high (CVSS 8.1) vulnerability in pydantic httpcore2. EPSS estimates a 0.08% chance of exploitation in the next 30 days, higher than 0.1% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.1, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.08%
0%100%
Low · -0.04 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 02-09-2026
    PublishedVulnerability first disclosed.
  2. 05-09-2026
    Last modifiedVulnerability information updated.

Description

HTTPX2 is a next generation HTTP client for Python. Prior to 2.10.0, httpcore2 fails to start TLS in src/httpcore2/httpcore2/_sync/socks_proxy.py and src/httpcore2/httpcore2/_async/socks_proxy.py when the remote origin uses wss through a SOCKS5 proxy because the TLS upgrade condition only recognizes https. HTTPX2 exposes the flaw through Client.websocket() and AsyncClient.websocket() from 2.6.0 through 2.9.1, so the opening handshake, query parameters, Authorization headers, cookies, and subsequent frames can cross the proxy path in plaintext without certificate verification. An attacker controlling or observing that path can read or modify traffic and impersonate the WebSocket server. This issue is fixed in httpcore2 2.10.0 and HTTPX2 2.10.0.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.08%

Chance of exploitation in the next 30 days

Percentile

0%

Versus all other CVEs

30-day change

Decrease -0.04 pp

From 0.11% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Pydantic2 products
PyPI2 products
  • httpcore2< 2.10.0
  • httpx2≥ 2.6.0, < 2.10.0
Ubuntu1 product
  • python-httpx2All versions (No fix recorded)

3 vendors · 5 products

References

11 links
Show all 11 references