CyberSecBulletin
CVE-2026-43910NVD status: Analyzed

java-client: Unintended Proxy or Intermediary

Published Updated By the CyberSecBulletin desk

CVE-2026-43910 is a high-severity unintended proxy or intermediary vulnerability in java-client from Appium, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected java-client versions: >= 8.2.1, < 10.1.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of java-client you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Appiumjava-client>= 8.2.1, < 10.1.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N. Scored by CNA (github.com).

Official description

Appium Java Client is the Java language binding for writing Appium tests that conform to the W3C WebDriver protocol. From 8.2.1 until 10.1.1, when directConnect(true) is enabled, AppiumCommandExecutor.setDirectConnect() reads the directConnectHost, directConnectPort, and directConnectPath fields from the server's NEW_SESSION response and rebuilds the client's server URL from them, validating only that the protocol is https, with no host allowlist or IP validation; a rogue or compromised server can therefore redirect all subsequent session traffic to an arbitrary destination, enabling full interception of session traffic and a server-side request forgery pivot to internal hosts, including cloud metadata (IMDS) credential theft. This vulnerability is fixed in 10.1.1.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Unintended Proxy or Intermediary

The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere.

How developers prevent this class of flaw

  • Enforce the use of strong mutual authentication mechanism between the two parties.
  • Whenever a product is an intermediary or proxy for transactions between two other components, the proxy core should not drop the identity of the initiator of the transaction. The immutability of the identity of the initiator must be maintained and should be forwarded all the way to the target.

More Unintended Proxy or Intermediary vulnerabilities (CWE-441)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Unintended Proxy or Intermediary vulnerabilities

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