CVE-2026-53899
Cross-origin cookies could be leaked when opening a PDF link
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Cross-origin cookies could be leaked when opening a PDF link
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
- Record
CVE-2026-53899- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-345
- Updated
- 2026-11-02
EUVDEUVD-2026-37077
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
- Record
EUVD-2026-37077- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-848m-8qg2-wmrv
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a...
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
- Record
GHSA-848m-8qg2-wmrv- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-345
- Updated
- 2026-11-02
NVD
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
- Record
CVE-2026-53899- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-345
- Updated
- 2026-11-02
OSV
Cross-origin cookies could be leaked when opening a PDF link
Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.
- Record
CVE-2026-53899- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53899 is a medium vulnerability (CVSS 6.5) in Mozilla Firefox For Ios, published June 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. No source names a fixed version.