Polkit: regression in cve-2026-4897 fix (polkit read_cookie()) - stack buffer underflow
Summary
| CVE | CVE-2026-85498 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-29 09:17:08 UTC |
| Updated | 2026-10-29 09:17:08 UTC |
| Description | A flaw was found in polkit. When processing input that begins with a null byte, an arithmetic error in the authentication agent helper causes an integer underflow during buffer length calculation, resulting in an out-of-bounds memory read. An attacker capable of supplying crafted input can trigger this flaw, potentially causing an application crash and resulting in a Denial of Service (DoS). |
Risk And Classification
Primary CVSS: v3.1 3.5 LOW from [email protected]
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Problem Types: CWE-125 | CWE-125 Out-of-bounds Read
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 3.5 | LOW | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 3.5 | LOW | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Hardened Images | unaffected 127-5.1.hum1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:66287 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-85498 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Juthawong Naisanguansee for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-09-04T00:40:47.865Z | Reported to Red Hat. |
| CNA | 2026-09-04T00:00:00.000Z | Made public. |
Workarounds
CNA: Mitigation for this issue is either not available or the currently available options do not meet the criteria for a mitigation as defined by the Red Hat Product Security team. This flaw remains subject to future review as new information becomes available. Exposure is limited: the defect is reachable only by a local/adjacent low-privileged user interacting with the polkit authentication agent and results at most in a crash (availability) of the affected process.
There are currently no legacy QID mappings associated with this CVE.