SB20260819111 - openEuler 20.03 LTS SP4 update for expat

Description

This security bulletin contains information about 3 vulnerabilities.

1) Protection mechanism failure (CVE-ID: CVE-2026-56131)

CWE-ID: CWE-693 - Protection Mechanism Failure

CVSSv4: 8.7 [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]

The vulnerability allows a remote attacker to cause memory corruption.

The vulnerability exists due to missing control flow integrity checks in XML_ResumeParser when it is called from a handler. A remote attacker can trigger a handler-driven call to XML_ResumeParser to cause memory corruption.

This issue is described as a hole in the fix for CVE-2026-50219.

2) Out-of-bounds write (CVE-ID: CVE-2026-56132)

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

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in doProlog when processing scaffolding index data. A remote attacker can supply crafted XML input to cause memory corruption.

3) Protection mechanism failure (CVE-ID: CVE-2026-50219)

CWE-ID: CWE-693 - Protection Mechanism Failure

CVSSv4: 8.7 [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]

The vulnerability allows a remote attacker to cause memory corruption.

The vulnerability exists due to missing control flow integrity checks in XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, and XML_ParserReset when these functions are called reentrantly from bindings or callbacks. A remote attacker can trigger unsafe parser API calls to cause memory corruption.

The issue is described as relevant to language bindings.

Remediation

Install update from vendor's website.

References

• https://www.openeuler.org/en/security/security-bulletins/detail/?id=openEuler-SA-2026-2857