Vulnerability · Published Oct 20, 2026 · Assigned by curl

CVE-2026-107928info leak uploading over WebSockets with GnuTLS

High 8.1

In plain English

A high-severity security flaw in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.7%top 46.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

When curl is built with GnuTLS, a malicious WebSocket server can make curl send memory past its send buffer. This is due to an out of bounds read following when `gnutls_record_send()` returns a number of bytes sent **greater than the number of bytes it was given to send**. GnuTLS does that after a blocked send.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.23curl8.23.0-r0ALPINE-CVE-2026-107928
Alpine:v3.24curl8.23.0-r0ALPINE-CVE-2026-107928
Debian:12curlno fix listedDEBIAN-CVE-2026-107928
Debian:13curlno fix listedDEBIAN-CVE-2026-107928
Debian:14curlno fix listedDEBIAN-CVE-2026-107928
Ubuntu:26.04:LTScurl8.18.0-1ubuntu2.8UBUNTU-CVE-2026-107928
Ubuntu:26.04:LTScurl8.18.0-1ubuntu2.8USN-8927-1
Ubuntu:26.10curl8.20.0-2ubuntu11.1UBUNTU-CVE-2026-107928
Ubuntu:26.10curl8.20.0-2ubuntu11.1USN-8927-2

Affected products (as reported)

VendorProductVersions
curl curl 8.22.0 – through 8.22.08.21.0 – through 8.21.08.20.0 – through 8.20.08.19.0 – through 8.19.08.18.0 – through 8.18.08.17.0 – through 8.17.08.16.0 – through 8.16.08.15.0 – through 8.15.0

Weakness: CWE-126 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References