CVE-2026-9545

Name
CVE-2026-9545
Description
In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL session (`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the `CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
2499f714-1537-4658-8207-48ae4bb9eae9 https://curl.se/docs/CVE-2026-9545.html
2499f714-1537-4658-8207-48ae4bb9eae9 https://curl.se/docs/CVE-2026-9545.json
2499f714-1537-4658-8207-48ae4bb9eae9 https://hackerone.com/reports/3752888

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* curl >= 8.11.0 < 8.21.0

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
curl edge-main 8.21.0-r0 Achill Gilgenast <achill@achill.org> fixed
curl edge-main 8.20.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.20.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.19.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.18.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.17.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.17.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.16.0-r2 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.16.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.16.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.15.0-r2 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.15.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl edge-main 8.15.0-r0 fossdd <fossdd@pwned.life> possibly vulnerable
curl edge-main 8.14.1-r2 fossdd <fossdd@pwned.life> possibly vulnerable
curl edge-main 8.14.1-r1 fossdd <fossdd@pwned.life> possibly vulnerable
curl edge-main 8.14.1-r0 fossdd <fossdd@pwned.life> possibly vulnerable
curl edge-main 8.14.0-r2 fossdd <fossdd@pwned.life> possibly vulnerable
curl edge-main 8.14.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.14.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.13.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.13.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.12.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.12.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.12.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.11.0-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl edge-main 8.11.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.24-main 8.21.0-r0 Achill Gilgenast <achill@achill.org> fixed
curl 3.24-main 8.20.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl 3.23-main 8.20.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl 3.23-main 8.19.0-r0 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl 3.23-main 8.17.0-r1 Achill Gilgenast <achill@achill.org> possibly vulnerable
curl 3.22-main 8.14.1-r3 fossdd <fossdd@pwned.life> possibly vulnerable
curl 3.22-main 8.14.1-r2 fossdd <fossdd@pwned.life> possibly vulnerable
curl 3.22-main 8.14.1-r1 fossdd <fossdd@pwned.life> possibly vulnerable
curl 3.22-main 8.14.1-r0 None possibly vulnerable
curl 3.22-main 8.14.0-r0 None possibly vulnerable
curl 3.22-main 8.12.0-r0 None possibly vulnerable
curl 3.22-main 8.11.1-r0 None possibly vulnerable
curl 3.22-main 8.11.0-r0 None possibly vulnerable
curl 3.21-main 8.14.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.14.1-r0 None possibly vulnerable
curl 3.21-main 8.14.0-r0 None possibly vulnerable
curl 3.21-main 8.12.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.12.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.12.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.11.0-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.21-main 8.11.0-r0 None possibly vulnerable
curl 3.20-main 8.14.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.14.1-r0 None possibly vulnerable
curl 3.20-main 8.14.0-r0 None possibly vulnerable
curl 3.20-main 8.12.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.12.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.11.0-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.20-main 8.11.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.14.1-r2 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.14.1-r0 None possibly vulnerable
curl 3.19-main 8.14.0-r0 None possibly vulnerable
curl 3.19-main 8.12.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.12.0-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.11.1-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.11.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
curl 3.19-main 8.11.0-r0 None possibly vulnerable