CVE-2026-42855
Last modified
CVE-2026-42855 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header, without verifying that it matches the actual requested URI. EPSS estimates a 0.35% chance of exploitation in the next 30 days.
Description
arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header, without verifying that it matches the actual requested URI. This allows an attacker who possesses any valid digest response (computed for URI-A) to authenticate requests to a completely different protected URI (URI-B), bypassing per-resource access control. This vulnerability is fixed in 3.3.8.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Espressif | Arduino-Esp32 | < 3.3.8 |
References
- https://github.com/espressif/arduino-esp32/security/advisories/GHSA-28hv-fwm3-rpcqExploit, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-42855?
How severe is CVE-2026-42855?
How do I fix CVE-2026-42855?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-42849authentik is an open-source identity provider. Prior to vers…9.3
- CVE-2026-4285A vulnerability was identified in taoofagi easegen-admin up …2.7
- CVE-2026-42850Kitty is a cross-platform GPU based terminal. In versions pr…8.8
- CVE-2026-42851Kitty is a cross-platform GPU based terminal. In versions pr…7.8
- CVE-2026-42853ApostropheCMS is an open-source Node.js content management s…6.5
- CVE-2026-42854arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ES…9.8
- CVE-2026-42856Network-AI is a TypeScript/Node.js multi-agent orchestrator.…8.7
- CVE-2026-42857Open edX Platform enables the authoring and delivery of onli…5.4
- CVE-2026-42858Open edX Platform enables the authoring and delivery of onli…9.9
- CVE-2026-42859Neat VNC is a VNC server library. Prior to 0.9.6, a pre-auth…8.1
- CVE-2026-4286Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fa…4.3
- CVE-2026-42860The Open edx Enterprise Service app provides enterprise feat…8.5
Are you affected by CVE-2026-42855?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST