CVE-2026-10050: Digest authentication lossy encoding

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-08-04 · updated 2026-08-08
Weakness: CWE-173

Description

In Eclipse Jetty, the Digest authentication server-side component uses ISO-8859-1 to encode the password as bytes. This was done because the initial specification for HTTP did not specify explicitly a charset, and it was assumed to be ISO-8859-1 for historical reasons. If the password contains characters that cannot be represented in ISO-8859-1, they are silently replaced by `?`. This happens with passwords that contain Chinese, Cyrillic or Greek characters, for example: `αβ123` converts to `??123`. An attacker can send a request with a digest `Authorization` header crafted with a password made of only `?` characters; the server would match any password of the same length that contains non-ISO-8859-1 characters. Recent HTTP Digest [RFC-7616](https://datatracker.ietf.org/doc/html/rfc7616) supports a `charset` parameters that defaults to UTF-8 that allows for correct encoding/decoding of passwords.

Affected products

The Eclipse Foundation Eclipse Jetty: from 9.4.0 before 9.4.63; from 10.0.0 before 10.0.31; from 11.0.0 before 11.0.31; from 12.0.0 before 12.0.36; from 12.1.0 before 12.1.10 — fixed in 10.0.31, 11.0.31, 12.0.36, 12.1.10, 9.4.63

How to fix

Upgrade to a fixed version: The Eclipse Foundation Eclipse Jetty 10.0.31, 11.0.31, 12.0.36, 12.1.10. Check the vendor advisory for mitigations.

References

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