Security readout for executives and security teams
Plain-English summary
FreeRDP versions before 3.20.1 can mishandle data while reading an RDPEAR NDR array, causing memory corruption. The published CVSS score is high because a network attacker may be able to affect confidentiality, integrity, and availability without authentication, although exploitation complexity is rated high.
Executive priority
Prioritize remediation for internet-reachable or high-trust systems using FreeRDP, but treat this as high rather than emergency unless local exposure or vendor intelligence changes.
Technical view
The flaw is a CWE-787 heap buffer overflow in ndr_read_uint8Array. The RDPEAR NDR array reader trusts an on-wire element count and can write beyond a heap buffer allocated from hints. FreeRDP fixed the issue in version 3.20.1.
Likely exposure
Exposure is limited to FreeRDP or downstream packages embedding FreeRDP before 3.20.1. Red Hat advisory references indicate distribution-level remediation tracking, but the provided bundle does not list exact downstream package versions or deployment roles.
Exploitation context
The CVSS vector is network, unauthenticated, no user interaction, high complexity, and unchanged scope. The source bundle does not show CISA KEV listing or other evidence of active exploitation, so active exploitation should not be assumed.
Researcher notes
Focus validation on version evidence and embedded dependencies. The key technical issue is missing bounds checking between on-wire element count and heap allocation hints in RDPEAR NDR parsing. No exploit details or proof-of-concept evidence were provided.
Mitigation direction
- Upgrade FreeRDP to 3.20.1 or later.
- Apply relevant Red Hat security errata where Red Hat packages are used.
- Inventory products that embed or bundle FreeRDP.
- Check vendor guidance for unsupported or appliance-managed FreeRDP builds.
Validation and detection
- Confirm installed FreeRDP versions are 3.20.1 or later.
- Check OS package status against applicable vendor errata.
- Review SBOMs for embedded FreeRDP below 3.20.1.
- Document any remaining affected systems and owner-approved timelines.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-22853 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9redhat-SADPCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P——GitHub_MVulnerability scoring details
Base CVSS 4.0 score
6.8MediumVector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-01-14T18:01:01.893Z: Reported to Red Hat.
- 2026-01-14T17:46:50.159Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-47v9-p4gp-w5chCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1CVE reference, GitHub_M · x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-22853CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2429647CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22853.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:4121CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:3068CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19033CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.