High severity7.5NVD Advisory· Published Jul 3, 2026· Updated Jul 7, 2026
CVE-2026-9546
CVE-2026-9546
Description
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.
Affected products
13- osv-coords11 versionspkg:apk/chainguard/eco-python-curlpkg:apk/chainguard/eco-python-curl-minimalpkg:apk/chainguard/eco-python-curl-minimal-binpkg:apk/chainguard/eco-python-curl-minimal-devpkg:apk/chainguard/eco-python-curl-minimal-docpkg:apk/chainguard/eco-python-curl-minimal-staticpkg:apk/chainguard/eco-python-curl-nghttp2pkg:apk/chainguard/eco-python-curl-nghttp2-binpkg:apk/chainguard/eco-python-curl-nghttp2-devpkg:apk/chainguard/eco-python-curl-nghttp2-staticpkg:rpm/opensuse/curl&distro=openSUSE%20Tumbleweed
< 8.21.0-r0+ 10 more
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-r0
- (no CPE)range: < 8.21.0-1.1
Patches
Vulnerability mechanics
References
3- curl.se/docs/CVE-2026-9546.htmlnvdPatchVendor Advisory
- hackerone.com/reports/3754343nvdExploitIssue TrackingThird Party Advisory
- curl.se/docs/CVE-2026-9546.jsonnvdThird Party Advisory
News mentions
1- 25-Year-Old Vulnerability in cURL Used by 30 Billion Devices Finally PatchedCyber Security News · Jun 25, 2026