Review reviewCritical

CVE-2026-8924

curl

A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.

CVSS
9.1
EPSS
0.65%
47.0% percentile
CISA KEV
Not listed
Published
2026.07.03
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.65%
Technical severityCVSS 9.1

Vulnerability overview

A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.

Affected product and versions

Product
curl
Affected versions
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
Fixed versions
8.21.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that curl and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE
Not available