CVE-2026-42855 (GCVE-0-2026-42855)
Vulnerability from cvelistv5 – Published: 2026-05-12 21:56 – Updated: 2026-05-13 15:36
VLAI
EPSS
VEX
Title
arduino-esp32: Digest authentication URI mismatch bypass in WebServer allows cross-resource replay attack
Summary
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.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-13 15:32 UTC
CWE
- CWE-287 - Improper Authentication
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/espressif/arduino-esp32/securi… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| espressif | arduino-esp32 |
Affected:
< 3.3.8
|
guessed |
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Nomenclature
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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