CVE-2026-29774 [Medium] | Out-of-bounds Write in Freerdp

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a client-side heap buffer overflow occurs in the FreeRDP client's AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates. In yuv.c, the clamp() function (line 347) only validates top/bottom against the surface/YUV height, but never checks left/right against the surface width. When avc420_yuv_to_rgb (line 67) computes destination and source pointers using rect->left, it performs unchecked pointer arithmetic that can reach far beyond the allocated surface buffer. A malicious server sends a WIRE_TO_SURFACE_PDU_1 with AVC420 codec containing a regionRects entry where left greatly exceeds the surface width (e.g., left=60000 on a 128px surface). The H.264 bitstream decodes successfully, then yuv420_process_work_callback calls avc420_yuv_to_rgb which computes pDstPoint = pDstData + rect->top * nDstStep + rect->left * 4, writing 16-byte SSE vectors 1888+ bytes past the allocated heap region. This vulnerability is fixed in 3.24.0.

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#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-19	0.04%	0.05%	+0.01%
2	2026-03-14	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-19

0.04%

0.05%

+0.01%

2026-03-14

—

0.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	3.9	1.4	[email protected]
8.2	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	4.2	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.3

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

3.9

1.4

[email protected]

8.2

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

4.2

[email protected]

OS Trackers for CVE-2026-29774

vendor	priority	summary	link
`alpine`	—	CVE-2026-29774: 1 source package rows (freerdp); 30 state rows across 2 repos (3.23-community, edge-community); fixed 2, open 28.	https://security.alpinelinux.org/vuln/CVE-2026-29774
`debian`	not yet assigned	CVE-2026-29774 not yet assigned priority: Debian including 2 source packages (freerdp2, freerdp3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2.	https://security-tracker.debian.org/tracker/CVE-2026-29774
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2026-29774
`suse`	medium	CVE-2026-29774 severity moderate: SUSE including 32 source package names (freerdp, freerdp-3.24.1-1.1, …), 47 product×package rows across 6 product lines (SUSE Linux Enterprise Module for Package Hub 15 SP7, SUSE Linux Enterprise Server 12 SP5-LTSS, … (6 product lines)): Known Not Affected 32, Fixed 15.	https://www.suse.com/security/cve/CVE-2026-29774/
`ubuntu`	medium	CVE-2026-29774 medium priority: Ubuntu including 3 source packages (freerdp, freerdp2, freerdp3), 16 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): needs-triage 10, DNE 5, released 1.	https://ubuntu.com/security/CVE-2026-29774

Affected software / configurations for CVE-2026-29774

Vendor	Product	Version	Raw CPE
freerdp	freerdp	< 3.24.0	cpe:2.3:a:freerdp:freerdp::::::::

References for CVE-2026-29774

URL	Tags
https://github.com/FreeRDP/FreeRDP/commit/6482b7a92fff3959582cef052d1967ad6bde3738	Patch
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5q35-hv9x-7794	Exploit Patch Vendor Advisory

URL

CVE-2026-29774 | FreeRDP has a heap-buffer-overflow in avc420_yuv_to_rgb via OOB regionRects

Public exploit references (Exploit-DB) for CVE-2026-29774

Exploit prediction scoring system (EPSS) score for CVE-2026-29774

Common vulnerability scoring system (CVSS) metrics for CVE-2026-29774

Weakness enumeration for CVE-2026-29774

OS Trackers for CVE-2026-29774

Affected software / configurations for CVE-2026-29774

References for CVE-2026-29774