FreeRDP: RDSTLS server authentication bypass: a credential-less Capabilities PDU is accepted at the auth step (fail-open `resultCode`)
FreeRDP · FreeRDP
8.3HighCVSS 4.0
Recommended action
Within 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available
Distribution package intelligence
Ubuntu vendor package status
Canonical’s release and source-package findings are shown separately from local repository availability.
2 package states
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
Ubuntu release
Source package
Vendor state
Fixed version
Evidence
Ubuntu 24.04 LTSnoble · esm-apps
freerdp2
Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.
Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2026-73241 · CSAF 2.0 · revision 3 · finalRed Hat Product SecurityFreeRDP: FreeRDP: Authentication bypass via incorrect RDSTLS PDU handling
65 fixed
The vendor explicitly identifies these products or versions as containing the fix.
freerdp-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-2:3.10.3-12.el10_2.10.src as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debugsource-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debugsource-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10)
freerdp-debugsource-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10)
Summary
A vulnerability in FreeRDP's server-side RDSTLS allows remote, unauthenticated attackers to bypass authentication. By sending a crafted capabilities PDU instead of the expected authentication request, an attacker can gain an authenticated session without valid credentials.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2026-56934
No EUVD known-exploited evidence
ENISA has published the identifier mapping but no EUVD description has been stored yet.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available
01
What, why and how
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP server-side RDSTLS in libfreerdp/core/rdstls.c accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ, leaving resultCode at RDSTLS_RESULT_SUCCESS and allowing a remote unauthenticated client to bypass the RedirectionGuid, username, domain, or password checks. This issue is fixed in version 3.30.0.
What
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP server-side RDSTLS in libfreerdp/core/rdstls.c accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ, leaving resultCode at RDSTLS_RESULT_SUCCESS and allowing a remote unauthenticated client to bypass the RedirectionGuid, username, domain, or password checks. This issue is fixed in version 3.30.0.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP server-side RDSTLS in libfreerdp/core/rdstls.c accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ, leaving resultCode at RDSTLS_RESULT_SUCCESS and allowing a remote unauthenticated client to bypass the RedirectionGuid, username, domain, or password checks. This issue is fixed in version 3.30.0.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
Likely attack path
a network path → Improper Authentication → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-287: Improper Authentication. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VILowVulnerable-system integrity: A successful attack can cause a limited loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-56934Official EUVD mapping
0 linked advisory records.
Official EUVD recordBSI · German · WID-SEC-W-2026-2776FreeRDP: Mehrere Schwachstellen
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in FreeRDP ausnutzen, um Informationen offenzulegen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder einen Denial-of-Service-Zustand auszulösen.
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
< 3.30.0
Fixed
freerdp-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.src as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); and 35 more
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 11 Aug 2026 · Last source change 13 Aug 2026, 14:51 UTC · CWE-287 · Improper Authentication
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-56934
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
freerdp as a component of Red Hat Enterprise Linux 10; freerdp-devel as a component of Red Hat Enterprise Linux 10; freerdp-libs as a component of Red Hat Enterprise Linux 10; freerdp-server as a component of Red Hat Enterprise Linux 10; freerdp.src as a component of Red Hat Enterprise Linux 10; libwinpr as a component of Red Hat Enterprise Linux 10; libwinpr-devel as a component of Red Hat Enterprise Linux 10
After
Fixed: freerdp-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.src as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-debugsource-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-libs-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); freerdp-server-debuginfo-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-2:3.10.3-12.el10_2.10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); libwinpr-debuginfo-2:3.10.3-12.el10_2.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); and 35 more
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
CVE-2026-73241: FreeRDP: RDSTLS server authentication bypass: a credential-less Capabilities PDU is accepted at the auth step (fail-open `resultCode`) | BlackTree
