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NVD / CVE Program· CNA VulnCheck

CVE-2026-56297: FreeRDP - Use-After-Free via Race Condition in DRDYNVC Channel Callback

HighCVSS 8.3 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 33/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.46% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: FreeRDP FreeRDP 3.22.0.

Low priority for now. Upgrade to FreeRDP FreeRDP 3.22.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

FreeRDP before 3.22.0 contains a use-after-free vulnerability in dvcman_channel_close and dvcman_call_on_receive due to improper synchronization of channel_callback access. A malicious RDP server can trigger a race condition by sending DYNVC_DATA and DYNVC_CLOSE messages concurrently, causing heap-use-after-free in the drdynvc client thread and potentially enabling remote code execution or denial of service.

Published
Jul 8, 2026
Updated
Oct 25, 2026
EPSS
0.4% · 40th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
8.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-56297

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
freerdpfreerdp

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • FreeRDP FreeRDP

    • 3.22.0not affected
    • before 3.22.0affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • freerdp freerdpbefore 3.22.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12freerdp2from 0—
Debian:13freerdp3from 0—
Debian:14freerdp3before 3.22.0+dfsg-13.22.0+dfsg-1
SUSE:Linux Enterprise Module for Package Hub 15 SP7freerdpbefore 3.10.3-150700.3.17.13.10.3-150700.3.17.1

Same product

freerdp: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-8787FreeRDP prior to version 2.0.0-rc4 contains an Integer Overflow that leads to a Heap-Based Buffer Overflow in function…
    42Plan
  • CVE-2018-8788FreeRDP prior to version 2.0.0-rc4 contains an Out-Of-Bounds Write of up to 4 bytes in function nsc_rle_decode() that results in a memory…
    41Plan
  • CVE-2018-8786FreeRDP prior to version 2.0.0-rc4 contains an Integer Truncation that leads to a Heap-Based Buffer Overflow in function…
    41Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-45700May 29, 2026 · Heap-buffer-overflow write in planar bitmap decoder
    32Monitor
  • ← EarlierCVE-2026-44420May 29, 2026 · FreeRDP cliprdr server heap-buffer-overflow via undersized capabilitySetLength in CB_CLIP_CAPS
    36Monitor
  • Later →CVE-2026-55827Jul 10, 2026 · FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
FreeRDP FreeRDP3.22.0Vendor (CNA)
debian:freerdp33.22.0+dfsg-1 · Debian:14Package registry (OSV)
suse:freerdp3.10.3-150700.3.17.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-121957119 days apartFreeRDP before 3.32.2 Use-After-Free via RDPGFX ResetGraphics Race
    34Monitor
  • CVE-2026-121961119 days apartFreeRDP before 3.32.2 Use-After-Free via DRDYNVC Tracker Race
    32Monitor
  • CVE-2026-121963119 days apartFreeRDP before 3.32.2 Use-After-Free via Dynamic rdpsnd Channel Close
    32Monitor
  • CVE-2026-9194769 days apartFreeRDP Server before 3.31.0 Use-After-Free via DRDYNVC
    30Monitor
  • CVE-2026-22851175 days apartFreeRDP RDPGFX ResetGraphics race leads to use-after-free in SDL client (sdl->primary)
    27Monitor
  • CVE-2026-22856175 days apartFreeRDP has a heap-use-after-free in create_irp_thread
    27Monitor

Not on record for this CVE: EPSS history · patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records