An update for shim is now available for openEuler-24.03-LTS Security Advisory openeuler-security@openeuler.org openEuler security committee openEuler-SA-2026-2080 Final 1.0 1.0 2026-04-25 Initial 2026-04-25 2026-04-25 openEuler SA Tool V1.0 2026-04-25 shim security update An update for shim is now available for openEuler-24.03-LTS Initial UEFI bootloader that handles chaining to a trusted full \ bootloader under secure boot environments. Security Fix(es): Issue summary: When a delta CRL that contains a Delta CRL Indicator extension is processed a NULL pointer dereference might happen if the required CRL Number extension is missing. Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application. When CRL processing and delta CRL processing is enabled during X.509 certificate verification, the delta CRL processing does not check whether the CRL Number extension is NULL before dereferencing it. When a malformed delta CRL file is being processed, this parameter can be NULL, causing a NULL pointer dereference. Exploiting this issue requires the X509_V_FLAG_USE_DELTAS flag to be enabled in the verification context, the certificate being verified to contain a freshestCRL extension or the base CRL to have the EXFLAG_FRESHEST flag set, and an attacker to provide a malformed CRL to an application that processes it. The vulnerability is limited to Denial of Service and cannot be escalated to achieve code execution or memory disclosure. For that reason the issue was assessed as Low severity according to our Security Policy. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.(CVE-2026-28388) An update for shim is now available for openEuler-24.03-LTS. openEuler Security has rated this update as having a security impact of high. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section. High shim https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2080 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-28388 https://nvd.nist.gov/vuln/detail/CVE-2026-28388 openEuler-24.03-LTS shim-15.7-26.oe2403.x86_64.rpm shim-debuginfo-15.7-26.oe2403.x86_64.rpm shim-debugsource-15.7-26.oe2403.x86_64.rpm shim-signed-15.7-26.oe2403.x86_64.rpm shim-15.7-26.oe2403.aarch64.rpm shim-debuginfo-15.7-26.oe2403.aarch64.rpm shim-debugsource-15.7-26.oe2403.aarch64.rpm shim-signed-15.7-26.oe2403.aarch64.rpm shim-15.7-26.oe2403.src.rpm Issue summary: When a delta CRL that contains a Delta CRL Indicator extension is processed a NULL pointer dereference might happen if the required CRL Number extension is missing. Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application. When CRL processing and delta CRL processing is enabled during X.509 certificate verification, the delta CRL processing does not check whether the CRL Number extension is NULL before dereferencing it. When a malformed delta CRL file is being processed, this parameter can be NULL, causing a NULL pointer dereference. Exploiting this issue requires the X509_V_FLAG_USE_DELTAS flag to be enabled in the verification context, the certificate being verified to contain a freshestCRL extension or the base CRL to have the EXFLAG_FRESHEST flag set, and an attacker to provide a malformed CRL to an application that processes it. The vulnerability is limited to Denial of Service and cannot be escalated to achieve code execution or memory disclosure. For that reason the issue was assessed as Low severity according to our Security Policy. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary. 2026-04-25 CVE-2026-28388 openEuler-24.03-LTS High 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H shim security update 2026-04-25 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2080