CVE•Published 2026-07-03•Modified 2026-07-07•1 article on news•4 live references•NVD data

CVE-2026-11856Haxx · Curl

Vulnerability data via NVD (ingested)

CVSS v3.1

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS percentile

Exploit Prediction Scoring System · top 84% of all CVEs

Weaknesses (CWE)

CWE-294Authentication Bypass by Capture-replay

Description

Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`.

Timeline

Published 2026-07-03

Modified 2026-07-07

External references

NVD MITRE Exploit-DB VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-11856

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Haxx Curl"

All exposed Haxx Curl instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Curl"

HTTP body or banner mentions "Curl" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-11856