SB20260819148 - Ubuntu update for curl

CSH
CYBERSECURITY HELP
Sign In REGISTER

Main Vulnerability Database SB20260819148

SB20260819148 - Ubuntu update for curl

Published: August 19, 2026

Security Bulletin ID SB20260819148
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Authentication Bypass by Capture-replay (CVE-ID: CVE-2026-11856)

CWE-ID: CWE-294 - Authentication Bypass by Capture-replay

CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to bypass authentication by replaying Digest authentication state.

The vulnerability exists due to authentication bypass by capture-replay in libcurl Digest authentication handling when reusing the same handle for a second transfer to a different HTTP origin. A remote attacker can receive a request containing an Authorization header intended for another origin to bypass authentication by replaying Digest authentication state.

The issue affects libcurl but not the curl command line tool. The leaked header does not reveal the other origin, and the exposed state allows replay only for the exact path of the captured request.


Remediation

Install update from vendor's website.

References