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

Red Hat Security Advisory: freerdp security update

Affects Red Hat freerdpSource GCVE Database

Compare

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 8.6 variants that fix these vulnerabilities. Users should apply the security update as detailed in Red Hat advisory RHSA-2026:4446 and the referenced article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated or required beyond applying the official update.

Description

Red Hat has issued a security advisory for FreeRDP, a free implementation of the Remote Desktop Protocol client. The advisory addresses three vulnerabilities involving heap and global buffer overflows (CVE-2026-22855, CVE-2026-22858, CVE-2026-22859) in FreeRDP. These vulnerabilities affect Red Hat Enterprise Linux 8.6 variants including Advanced Mission Critical Update Support, Update Services for SAP Solutions, and Telecommunications Update Service. The vulnerabilities have been rated with an important security impact by Red Hat. Updates to FreeRDP packages are available to remediate these issues.

Impact

The vulnerabilities involve heap and global buffer overflows in FreeRDP, which may lead to memory corruption. Such issues can cause application crashes or potentially enable further exploitation depending on the context. Red Hat rates the security impact as important, indicating a high severity but not critical. There are no known exploits in the wild at the time of the advisory.

Summary

This advisory covers three security flaws in FreeRDP, specifically heap-buffer-overflow and global-buffer-overflow vulnerabilities identified as CVE-2026-22855, CVE-2026-22858, and CVE-2026-22859. FreeRDP is an open-source RDP client used to connect to various RDP servers. The vulnerabilities could allow memory corruption issues, potentially leading to crashes or other unintended behavior. Red Hat has released updated FreeRDP packages for Red Hat Enterprise Linux 8.6 variants to address these issues. The advisory references bugzilla entries and provides package updates for affected architectures. No CVSS scores are provided in the advisory, but the impact is rated as important by Red Hat Product Security.

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

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 18 Aug 2026, 13:57 UTC

WeaknessesCWE-125, CWE-787

Technical details

References

Community reviews

Related threats