CVSS 3.1
5.9 mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:HCVE-2026-122056 Openscap: one-byte heap buffer overflow in sds-compose may lead to denial-of-service
Medium (5.9) in red hat. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
A flaw was found in OpenSCAP. A heap-based buffer overflow can occur when processing a specially crafted Extensible Configuration Checklist Description Format (XCCDF) document using the sds-compose option. An attacker could exploit this vulnerability to corrupt memory, resulting in an application crash and a Denial of Service (DoS).
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 26th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-787 Out-of-bounds Write
- Published
- Modified
- Assigned by
- redhat (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- red hat:red hat enterprise linux 10
- red hat:red hat enterprise linux 6
- red hat:red hat enterprise linux 7
- red hat:red hat enterprise linux 8
- red hat:red hat enterprise linux 9
- red hat:red hat hardened images
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | openscap | no fix listed | DEBIAN-CVE-2026-122056 |
| Ubuntu | 18.04:LTS, 20.04:LTS, 22.04:LTS and 4 more | openscap | no fix listed | UBUNTU-CVE-2026-122056 |
| Azure Linux | 3 | openscap | no fix listed | AZL-113570 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Microsoft's Azure Linux vulnerability data, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.
Red Hat
Red Hat rates this Moderate.
This vulnerability is rated as Moderate severity rather than Low because heap memory corruption can cause the scanning utility to terminate unexpectedly during datastream composition tasks. OpenSCAP operates as a local command-line tool rather than an always-on listening daemon, limiting network exposure since the flaw cannot be triggered passively without administrative interaction. Exploitation requires an administrator or automated workflow to process an untrusted, malformed XCCDF document via the `sds-compose` operation, restricting the overall impact to the disruption of the composing process.
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.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | openscap | Fix deferred | |
| Red Hat Enterprise Linux 6 | openscap | Out of support scope | |
| Red Hat Enterprise Linux 7 | openscap | Fix deferred | |
| Red Hat Enterprise Linux 8 | openscap | Fix deferred | |
| Red Hat Enterprise Linux 9 | openscap | Fix deferred | |
| Red Hat Hardened Images | openscap | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-122056.
GitHub PoC (unverified)
Repositories on GitHub named after this CVE. Nobody has checked them and they are not scanned: some hold a working proof of concept, some nothing useful, and some malware made to look like one. Read the code before you run any of it.
- D7EAD/CVE-2026-122056 1 star, created
A flaw was found in OpenSCAP. A heap-based buffer overflow can occur when processing a specially crafted XCCDF document.