9.8

CVE-2026-19931: curl

CVSS: 9.8v3.1CriticalModified
AliasesALPINE-CVE-2026-19931UBUNTU-CVE-2026-19931DEBIAN-CVE-2026-19931
Published 06-09-2026Last modified 15-09-2026
Open JSON

Vulnerability summary

CVE-2026-19931 is a critical (CVSS 9.8) vulnerability in curl. EPSS estimates a 0.75% chance of exploitation in the next 30 days, higher than 54.2% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.75%
0%100%
Low · -0.41 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 4 · Related 1
MGASA-2026-0515OPENSUSE-SU-2026:11696-1RHSA-2026:63161RHSA-2026:63514

Timeline

  1. 06-09-2026
    PublishedVulnerability first disclosed.
  2. 15-09-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.75%

Chance of exploitation in the next 30 days

Percentile

54%

Versus all other CVEs

30-day change

-0.41 pp

From 1.16% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.75%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (hackerone.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Chainguard2 products
  • curl< 8.22.0-r0
  • libcurl4All versions (No fix recorded)
Wolfi2 products
  • curl< 8.22.0-r0
  • libcurl4All versions (No fix recorded)
Alpine1 product
  • curl≥ 7.64.1, < 8.22.0-r0
Curl1 product
  • curl≥ 7.64.1, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.20.1 | ≥ 8.21.0, < 8.22.0 | ≥ 6c6035532383e300c712e4c1cd9fdd749ed5cf59, < 7103a93b05bc69ea98ed9d05d02fa9eeba533f2f | 8.21.0 | 8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0 | 8.7.1 | 8.7.0 | 8.6.0 | 8.5.0 | 8.4.0 | 8.3.0 | 8.2.1 | 8.2.0 | 8.1.2 | 8.1.1 | 8.1.0 | 8.0.1 | 8.0.0 | 7.88.1 | 7.88.0 | 7.87.0 | 7.86.0 | 7.85.0 | 7.84.0 | 7.83.1 | 7.83.0 | 7.82.0 | 7.81.0 | 7.80.0 | 7.79.1 | 7.79.0 | 7.78.0 | 7.77.0 | 7.76.1 | 7.76.0 | 7.75.0 | 7.74.0 | 7.73.0 | 7.72.0 | 7.71.1 | 7.71.0 | 7.70.0 | 7.69.1 | 7.69.0 | 7.68.0 | 7.67.0 | 7.66.0 | 7.65.3 | 7.65.2 | 7.65.1 | 7.65.0 | 7.64.1
Debian1 product
  • curlAll versions (No fix recorded) | < 8.22.0~rc2-1
Haxx1 product
  • curl≥ 7.64.1, < 8.22.0
Ubuntu1 product
  • curlAll versions (No fix recorded)

7 vendors · 9 products

References

10 links