Ghostscript: reintroduction of .charkeys -dsafer bypass in rhel 8
Summary
| CVE | CVE-2026-112177 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-20 08:16:42 UTC |
| Updated | 2026-11-04 22:17:48 UTC |
| Description | A flaw was found in Ghostscript as shipped with Red Hat Enterprise Linux 8. The correction for CVE-2019-14869 was omitted during the rebase from version 9.25 to 9.27, leaving privileged .forceput operations in the .charkeys procedure insufficiently protected. Processing a specially crafted PostScript file may allow an attacker to bypass -dSAFER restrictions and access files outside the permitted paths or execute commands with the permissions of the Ghostscript process. |
Risk And Classification
Primary CVSS: v3.1 7.3 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS: 0.003600000 probability, percentile 0.299410000 (date 2026-11-04)
Problem Types: CWE-648 | CWE-648 Incorrect Use of Privileged APIs
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | CNA | CVSS | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 0:9.27-20.el8_10 * rpm | 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 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:93978 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-112177 | [email protected] | access.redhat.com | |
| github.com/ArtifexSoftware/ghostpdl/commit/485904772c5f0aa1140032746e5a0... | [email protected] | github.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 Nicholas Pettas for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-10-12T21:01:02.000Z | Reported to Red Hat. |
| CNA | 2026-10-20T07:04:46.757Z | Made public. |
Workarounds
CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. --- CME Mitigation Guidance (2026-10-20) --- Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. The highest-value action is to eliminate privileged .forceput operations in the .charkeys procedure to enforce -dSAFER sandbox boundaries: upgrade to the fixed Ghostscript builds, which replace .forceput invocations with standard put operations in the /.charkeys procedure in Resource/Init/gs_ttf.ps, closing all 2 injection vectors (crafted PostScript document, malicious TrueType font processing). Until patched, this is a concern on Ghostscript on Linux (RHEL 8) processing untrusted input, such as print or document-conversion services, so Restrict or halt processing of untrusted PostScript documents and TrueType font inputs across document-conversion and printing services that invoke Ghostscript. As a compensating measure, Use auditd to log unauthorized file access attempts and unexpected execve syscalls spawned by the Ghostscript process, Run SELinux in enforcing mode to confine the Ghostscript process to a restricted domain, Use Linux mount and PID namespaces to restrict filesystem and process visibility for Ghostscript execution, Deploy an EDR agent to detect and terminate unexpected shell or child process spawns from Ghostscript, and Use Falco or eBPF runtime security to detect anomalous child process execution and unauthorized file reads. These controls limit blast radius and contain exploitation, but they do not fix the underlying privileged .forceput sandbox bypass — apply the upstream patch to fully remediate. Highest-impact CME: CME-1002 Audit Subsystem (auditd) (medium)