CVE-2025-9086
Description
1. A cookie is set using the `secure` keyword for `https://target` 2. curl is redirected to or otherwise made to speak with `http://target` (same hostname, but using clear text HTTP) using the same cookie set 3. The same cookie name is set - but with just a slash as path (`path=\"/\",`). Since this site is not secure, the cookie *should* just be ignored. 4. A bug in the path comparison logic makes curl read outside a heap buffer boundary The bug either causes a crash or it potentially makes the comparison come to the wrong conclusion and lets the clear-text site override the contents of the secure cookie, contrary to expectations and depending on the memory contents immediately following the single-byte allocation that holds the path. The presumed and correct behavior would be to plainly ignore the second set of the cookie since it was already set as secure on a secure host so overriding it on an insecure host should not be okay.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 6 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 8.14.1-2+deb13u1 |
| sid | Fixed | 8.16.0~rc2-1 |
| forky | Fixed | 8.16.0~rc2-1 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 0 |
| 11.0 | Affected | — |
Red Hat Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
| 8 | Fixed | — |
Rocky Linux Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
| 8 | Fixed | — |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| haxx | curl | {"startIncluding":"8.13.0","endExcluding":"8.16.0"} | 8.16.0 |
References
- https://errata.rockylinux.org/RLSA-2025:23383
- https://access.redhat.com/errata/RHSA-2026:1350
- https://security-tracker.debian.org/tracker/CVE-2025-9086
- https://www.suse.com/security/cve/CVE-2025-9086.html
- https://errata.rockylinux.org/RLSA-2026:1350
- https://access.redhat.com/errata/RHSA-2025:23383
- https://bugzilla.redhat.com/2394750
- https://errata.almalinux.org/8/ALSA-2025-23383.html
- https://errata.almalinux.org/9/ALSA-2026-1350.html
- https://curl.se/docs/CVE-2025-9086.html
- https://curl.se/docs/CVE-2025-9086.json
- https://hackerone.com/reports/3294999
- http://www.openwall.com/lists/oss-security/2025/09/10/1
- https://lists.debian.org/debian-lts-announce/2026/01/msg00002.html
- https://cert-portal.siemens.com/productcert/html/ssa-089022.html
- https://cert-portal.siemens.com/productcert/html/ssa-253495.html
CWEs
CWE-125
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.