Vulnerability · Published Mar 11, 2026 · Assigned by curl
CVE-2026-3805use after free in SMB connection reuse
High 7.5
In plain English
A high-severity use-after-free in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 60% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.9%top 40.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack tooling1Public PoC
Official description
When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.21 | curl | 8.14.1-r3 | ALPINE-CVE-2026-3805 |
| Alpine:v3.22 | curl | 8.14.1-r4 | ALPINE-CVE-2026-3805 |
| Alpine:v3.23 | curl | 8.19.0-r0 | ALPINE-CVE-2026-3805 |
| Alpine:v3.24 | curl | 8.19.0-r0 | ALPINE-CVE-2026-3805 |
| Debian:13 | curl | 8.14.1-2+deb13u4 | DEBIAN-CVE-2026-3805 |
| Debian:14 | curl | 8.19.0-1 | DEBIAN-CVE-2026-3805 |
| Ubuntu:22.04:LTS | curl | 7.81.0-1ubuntu1.23 | USN-8084-1 |
| Ubuntu:24.04:LTS | curl | 8.5.0-2ubuntu10.8 | USN-8084-1 |
| Ubuntu:25.10 | curl | 8.14.1-2ubuntu1.2 | USN-8084-1 |
| Ubuntu:25.10 | curl | 8.14.1-2ubuntu1.2 | UBUNTU-CVE-2026-3805 |
Affected products (as reported)
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H