CVE-2026-22855VulnerabilityPublished 12 Mar 2026Updated 18 Aug 2026

Red Hat Security Advisory: freerdp security update

Affects Red Hat freerdpSource GCVE Database

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Mentioned vulnerabilities

Not known to be exploited.

Data as of 30 Oct 2026, 11:52 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.8% chance of exploitation in 30 days – higher than 59% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Red Hat has released updated freerdp packages for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions that address these vulnerabilities. Users should apply these official patches as soon as possible to remediate the issues. Detailed instructions and package links are available in the Red Hat advisory RHSA-2026:4437 at https://access.redhat.com/errata/RHSA-2026:4437. No additional mitigation steps are indicated by the vendor advisory.

Description

Multiple heap and global buffer overflow vulnerabilities have been identified in FreeRDP, a free implementation of the Remote Desktop Protocol client. These vulnerabilities are tracked as CVE-2026-22855, CVE-2026-22858, and CVE-2026-22859. Red Hat has issued a security advisory for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions, providing updated freerdp packages to address these issues. The vulnerabilities could potentially lead to memory corruption. No CVSS scores are provided in the advisory. Red Hat rates the update as important and has released patches to remediate the vulnerabilities.

Impact

Successful exploitation of these heap and global buffer overflow vulnerabilities could result in memory corruption within the FreeRDP client. This may lead to application crashes or potentially allow an attacker to execute arbitrary code or cause denial of service. The advisory does not provide explicit details on exploitation or impact severity beyond the 'Important' rating by Red Hat Product Security. No known active exploitation is reported at this time.

Summary

The security advisory from Red Hat addresses three vulnerabilities in FreeRDP: two heap-buffer-overflows (CVE-2026-22855 and CVE-2026-22859) and one global-buffer-overflow (CVE-2026-22858). FreeRDP is an open-source Remote Desktop Protocol client used to connect to RDP servers such as Microsoft Windows, xrdp, and VirtualBox. The advisory provides updated packages for Red Hat Enterprise Linux 9.2 variants, including x86_64, ppc64le, aarch64, and s390x architectures. These vulnerabilities are related to improper memory handling that could lead to buffer overflows. The advisory references Red Hat Bugzilla entries for each CVE and directs users to apply the updated freerdp packages to mitigate the issues. No evidence of known exploits in the wild is reported.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 18 Aug 2026, 13:58 UTC

WeaknessesCWE-125, CWE-787

Technical details

References

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