CVE-2026-85089: FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info

Routine

MEDIUM 6.5UPGRADE

CVE-2026-85089 is a medium-severity flaw (CVSS 6.5) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and rdp_write_logon_info_ex) use Stream_Seek instead of Stream_Zero for reserved pad bytes (up to 576 bytes), leaving previously freed heap contents in the outgoing PDU. Because the send buffer is allocated with m

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-908
Published	2026-09-03
Last modified	2026-09-09

Publisher (CNA): VulnCheck · Vendor: freerdp

Last updated 2026-09-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-03 13:06 UTCPublished CVE record published
2026-09-09 19:12 UTCUpdated Record last modified

freerdp freerdp UPGRADE

Affected: >= 3.0.0 and < 3.31.0

Fixed in: 3.31.0

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy freerdp || rpm -q freerdp || freerdp --version

2. UPGRADE to 3.31.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade freerdp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freerdp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison freerdp sudo apt install freerdp=<VERSION_BEFORE_3.0.0> sudo apt-mark hold freerdp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list freerdp sudo dnf downgrade freerdp-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add freerdp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Advisories and coverage

Official advisories

Amazon Linux 2 ALAS: ALAS2-2026-3938 (important): freerdp 2026-09-28

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-85089?

freerdp: upgrade to 3.31.0. Exact commands for each OS are on this page.

Is CVE-2026-85089 being exploited?

CVE-2026-85089 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-85089 affect?

CVE-2026-85089 affects freerdp. Severity is medium (CVSS 6.5). FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and

How urgent is CVE-2026-85089?

Priority 36/100. Public exploit reference

Software pages

WinRM and RDP vulnerabilities

Related CVEs

CVE-2026-109940 MEDIUM 4.3 UPGRADE FreeRDP 3.0.0-beta1 before 3.32.0 on Unix builds with PKCS#11 support has a stack-based buffer overflow in wpr
CVE-2026-109939 MEDIUM 6.5 UPGRADE FreeRDP 3.27.1 before 3.32.0 contains a NULL pointer dereference in update_read_cache_bitmap_v3_order() in lib
CVE-2026-109938 MEDIUM 6.5 UPGRADE Positive mapped-video coordinates overflow and abort FreeRDP clients A malicious or compromised RDP server can
CVE-2026-109941 MEDIUM 6.5 UPGRADE FreeRDP from 2.3.0 before 3.32.0 contains an infinite loop vulnerability in http_chuncked_read that allows mal
CVE-2026-109942 MEDIUM 6.5 UPGRADE FreeRDP 2.3.0 before 3.32.0 dereferences a NULL stream in rdg_process_close_packet in libfreerdp/core/gateway/

References

← Back to latest CVEs