CVE-2025-20128 [Medium] | Denial of Service in Clamav

A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an integer underflow in a bounds check that allows for a heap buffer overflow read. An attacker could exploit this vulnerability by submitting a crafted file containing OLE2 content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process, resulting in a DoS condition on the affected software. For a description of this vulnerability, see the . Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.99%	1.46%	-0.53%
2	2026-05-20	1.62%	1.99%	+0.36%
3	2026-03-02	—	1.62%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.99%

1.46%

-0.53%

2026-05-20

1.62%

1.99%

+0.36%

2026-03-02

—

1.62%

—

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]
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[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]

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

OS Trackers for CVE-2025-20128

vendor	priority	summary	link
`alpine`	medium	CVE-2025-20128: 1 source package rows (clamav); 4 state rows across 3 repos (3.21-community, 3.22-community, edge-community); fixed 3, open 1.	https://security.alpinelinux.org/vuln/CVE-2025-20128
`debian`	not yet assigned	CVE-2025-20128 not yet assigned priority: Debian including 1 source packages (clamav), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2025-20128
`suse`	medium	CVE-2025-20128 severity moderate: SUSE including 48 source package names (clamav, clamav-1.4.2-1.1, …), 212 product×package rows across 37 product lines (Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, Image SLES12-SP5-SAP-Azure-VLI-BYOS-Production, … (37 product lines)): Fixed 197, Known Not Affected 15.	https://www.suse.com/security/cve/CVE-2025-20128/
`ubuntu`	medium	CVE-2025-20128 medium priority: Ubuntu including 1 source packages (clamav), 8 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): not-affected 5, released 3.	https://ubuntu.com/security/CVE-2025-20128

Affected software / configurations for CVE-2025-20128

Vendor	Product	Version	Raw CPE
clamav	clamav	>= 1.0.0, < 1.0.8	cpe:2.3:a:clamav:clamav::::::::
clamav	clamav	>= 1.1.0, < 1.4.2	cpe:2.3:a:clamav:clamav::::::::
cisco	secure_endpoint	< 1.24.4	cpe:2.3:a:cisco:secure_endpoint::::::macos::*
cisco	secure_endpoint	< 1.25.1	cpe:2.3:a:cisco:secure_endpoint::::::linux::*
cisco	secure_endpoint	< 7.5.20	cpe:2.3:a:cisco:secure_endpoint::::::windows::*
cisco	secure_endpoint	>= 8.0.1.21160, < 8.4.3	cpe:2.3:a:cisco:secure_endpoint::::::windows::*
cisco	secure_endpoint_private_cloud	< 4.2.0	cpe:2.3:a:cisco:secure_endpoint_private_cloud::::::::

References for CVE-2025-20128

URL	Tags
https://blog.clamav.net/2025/01/clamav-142-and-108-security-patch.html	Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-ole2-H549rphA	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/09/msg00006.html

URL

CVE-2025-20128 | ClamAV OLE2 File Format Decryption Denial of Service Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2025-20128

Common vulnerability scoring system (CVSS) metrics for CVE-2025-20128

Weakness enumeration for CVE-2025-20128

OS Trackers for CVE-2025-20128

Affected software / configurations for CVE-2025-20128

References for CVE-2025-20128