CVE-2026-9546
CVE-2026-9546 · sending old referer
This page contains facts from public vulnerability sources. Check the original advisory before updating.
A vulnerability in libcurl caused the HTTP `Referer:` header to persist even when explicitly cleared. While the documentation states that passing NULL to `CURLOPT_REFERER` suppresses the header, the option failed to clear the internal state. As a result, the previous referrer string was erroneously reused and sent in subsequent requests, potentially leaking sensitive information to unintended servers.
CVSS 7.5 · High · EPSS 0.7% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
curl
- Versions
- ≥ 8.18.0, < 8.20.1: Affected (semver)
Update to 8.20.1
curl
- Versions
- ≥ 2cb868242dc2ac9cd52ee64987ef51d5964a56f9, < 862e8a74a84478d82973471b4f49dc2746c1780e: Affected (git)
No fix published
curl
- Versions
- 8.20.0: Affected
- 8.19.0: Affected
- 8.18.0: Affected
No fix published
curl Debian:14
- Versions
- 8.14.1-2
- 8.14.1-2+exp1
- 8.15.0-1
- 8.15.0-1~bpo13+1
- 8.15.0-1~exp1
- 8.15.0~rc1-1exp1
- 8.15.0~rc2-1~exp1
- 8.15.0~rc3-1~exp1
- 8.16.0-1
- 8.16.0-1+exp1
- 8.16.0-1~bpo13+1
- 8.16.0-2
- 8.16.0-3
- 8.16.0-4
- 8.16.0-4~bpo13+1
- 8.16.0~rc1-1~exp1
- 8.16.0~rc2-1
- 8.16.0~rc2-2
- 8.16.0~rc3-1
- 8.17.0-1
- 8.17.0-2
- 8.17.0-3
- 8.17.0~rc1-1~exp1
- 8.17.0~rc2-1
- 8.17.0~rc3-1
- 8.18.0-1
- 8.18.0-1~bpo13+1
- 8.18.0-2
- 8.18.0~rc1-1+exp1
- 8.18.0~rc2-1
- 8.18.0~rc3-1
- 8.19.0-1
- 8.19.0-1+exp1
- 8.19.0-1~bpo13+1
- 8.19.0-2
- 8.19.0-3
- 8.19.0-3+exp1
- 8.19.0-3+exp2
- 8.19.0~rc1-1~exp1
- 8.19.0~rc2-1
- 8.19.0~rc2-2
- 8.19.0~rc3-1
- 8.20.0-1
- 8.20.0-1+exp
- 8.20.0-2
- 8.20.0-2+exp1
- 8.20.0-2~bpo13+1
- 8.20.0-3
- 8.20.0-4
- 8.20.0-5
- 8.20.0-5~bpo13+1
- 8.20.0~rc1-1+exp1
- 8.20.0~rc1-1+exp2
- 8.20.0~rc1-1+exp3
- 8.20.0~rc2-1
- 8.20.0~rc2-1+exp1
- 8.20.0~rc3-1
- 8.20.0~rc3-1+exp1
- 8.21.0~rc1-1+exp1
- Affected ranges
- ECOSYSTEM: < 8.21.0~rc2-1
Update to 8.21.0~rc2-1