Riskcovery

CVE-2026-19931

Negotiate ambient user conn reuse

State
Published
Severity
9.8 Critical
Published
Sep 6, 2026
Updated
Sep 15, 2026
Reserved
Aug 15, 2026

Read the record on cve.org

Description

A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCISA-ADP

Weaknesses

  • CWE-488 Exposure of Data Element to Wrong Session

Affected Products

ProductVersions
curlcurl
  • 7.64.1 to before 8.14.2Affected
  • 8.15.0 to before 8.16.1Affected
  • 8.17.0 to before 8.20.1Affected
  • 8.21.0 to before 8.22.0Affected
curlcurl
  • 6c6035532383e300c712e4c1cd9fdd749ed5cf59 to before 7103a93b05bc69ea98ed9d05d02fa9eeba533f2fAffected
curlcurl
  • 8.21.0Affected
  • 8.20.0Affected
  • 8.19.0Affected
  • 8.18.0Affected
  • 8.17.0Affected
  • 8.16.0Affected
  • 8.15.0Affected
  • 8.14.1Affected
  • 8.14.0Affected
  • 8.13.0Affected
  • 8.12.1Affected
  • 8.12.0Affected
  • 8.11.1Affected
  • 8.11.0Affected
  • 8.10.1Affected
  • 8.10.0Affected
  • 8.9.1Affected
  • 8.9.0Affected
  • 8.8.0Affected
  • 8.7.1Affected
  • 8.7.0Affected
  • 8.6.0Affected
  • 8.5.0Affected
  • 8.4.0Affected
  • 8.3.0Affected
  • and 41 more versions

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.