SB20261001118 - Ubuntu update for clamav

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Main Vulnerability Database SB20261001118

SB20261001118 - Ubuntu update for clamav

Published: October 1, 2026

Security Bulletin ID SB20261001118
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 7
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 7 vulnerabilities.


1) Out-of-bounds write (CVE-ID: CVE-2026-20337)

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

CVSSv4: 6.7 [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]


The vulnerability allows a remote attacker to write beyond a heap allocation.

The vulnerability exists due to out-of-bounds write in ZIP catalogue capacity tracking when indexing local file headers. A remote attacker can provide a crafted ZIP archive to write beyond a heap allocation.


2) Double free (CVE-ID: CVE-2026-20338)

CWE-ID: CWE-415 - Double Free

CVSSv4: 6.7 [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]


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

The vulnerability exists due to invalid free in ZIP catalogue record merging when scanning a malformed archive. A remote attacker can provide a crafted archive to cause a denial of service.


3) Integer overflow (CVE-ID: CVE-2026-20339)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: 6.7 [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]


The vulnerability allows a remote attacker to write beyond an undersized buffer.

The vulnerability exists due to integer overflow in the PESpin unpacker when rebuilding a PE file. A remote attacker can provide a crafted PE file to write beyond an undersized buffer.


4) Out-of-bounds write (CVE-ID: CVE-2026-20345)

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

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to read or write beyond a stack-allocated partition entry.

The vulnerability exists due to out-of-bounds read and out-of-bounds write in GPT partition name conversion when parsing partition names. A remote attacker can provide a crafted GPT structure to read or write beyond a stack-allocated partition entry.


5) Integer underflow (CVE-ID: CVE-2026-20346)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: 6.7 [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]


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

The vulnerability exists due to integer underflow in the PDF parser when reading a malformed hex string. A remote attacker can provide a crafted PDF input to cause a denial of service.


6) Integer overflow (CVE-ID: CVE-2026-20347)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: 6.7 [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]


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

The vulnerability exists due to integer overflow in the Mach-O parser when scanning a malformed Mach-O file. A remote attacker can provide a crafted Mach-O file to cause a denial of service.

The advisory also mentions undefined behavior in the affected parser.


7) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-20348)

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

CVSSv4: 6.7 [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]


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

The vulnerability exists due to improper size handling in the XAR parser when decompressing a malformed table of contents. A remote attacker can provide a crafted XAR archive to cause a denial of service.

The issue can request an excessive allocation or exceed scan limits.


Remediation

Install update from vendor's website.

References