SB2026070169 - Multiple vulnerabilities in ClamAV



SB2026070169 - Multiple vulnerabilities in ClamAV

Published: July 1, 2026

Security Bulletin ID SB2026070169
CSH Severity
High
Patch available
YES
Number of vulnerabilities 8
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 38% Medium 63%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 8 vulnerabilities.


1) Release of invalid pointer or reference (CVE-ID: CVE-2026-20217)

CWE-ID: CWE-763 - Release of invalid pointer or reference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to invalid pointer free in the PESpin unpacker cleanup path when scanning a crafted PE file. A remote attacker can provide a specially crafted file to cause a denial of service.


2) Integer overflow (CVE-ID: CVE-2026-20213)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to integer overflow in PE rebuild size calculations when scanning a malformed Aspack-packed PE file. A remote attacker can provide a specially crafted file to execute arbitrary code.


3) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-20216)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper enforcement of extraction limits in InstallShield archive handling when scanning a crafted InstallShield archive. A remote attacker can provide a specially crafted archive to cause a denial of service.

The issue can exhaust temporary storage by writing far more temporary data than intended.


4) Integer underflow (CVE-ID: CVE-2026-20214)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to integer underflow in the FSG unpacker loop when scanning a malformed PE file. A remote attacker can provide a specially crafted file to execute arbitrary code.

The issue can write past the section array.


5) Input validation error (CVE-ID: CVE-2026-20243)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper size handling in the ALZ parser when parsing a malformed ALZ archive. A remote attacker can provide a specially crafted archive to cause a denial of service.

The issue may panic or abort the scanner, and it may also skip expected scan-limit handling.


6) Integer overflow (CVE-ID: CVE-2026-20215)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to integer overflow in the 7z parser substream count handling when parsing a malformed archive. A remote attacker can provide a specially crafted archive to execute arbitrary code.

The issue can under-allocate parser metadata arrays and write past them while reading the archive.


7) Input validation error (CVE-ID: CVE-2026-20244)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper size checks in the DMG parser when parsing a crafted DMG file on 32-bit builds. A remote attacker can provide a specially crafted file to cause a denial of service.

Only 32-bit scanner builds are affected.


8) Out-of-bounds write (CVE-ID: CVE-2026-41676)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a buffer overflow.

The vulnerability exists due to a heap/stack overflow in Deriver::derive and PkeyCtxRef::derive when deriving shared secrets into a caller-supplied buffer on OpenSSL 1.1.x. A remote attacker can provide or trigger use of a short buffer to cause a buffer overflow.

Only OpenSSL 1.1.x is affected; OpenSSL 3.x providers check the buffer length.


Remediation

Install update from vendor's website.