{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-12235", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-06-15T01:56:05.689Z", "datePublished": "2026-08-12T04:55:15.620Z", "dateUpdated": "2026-08-12T12:34:55.518Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-12T04:55:15.620Z"}, "title": "Out-of-bounds write in Xtensa llext PLT relocation from malformed ELF (CWE-787)", "descriptions": [{"lang": "en", "value": "The Linkable Loadable Extensions (llext) subsystem mis-handles PLT/RELA relocation entries when linking a relocatable (partially-linked) ELF extension. In llext_link_plt() (subsys/llext/llext_link.c), the relocatable branch (tgt != NULL, the path used for Xtensa relocatable objects) computed the patch address as ext->mem[LLEXT_MEM_TEXT] - text.sh_offset + rela.r_offset + tgt->sh_offset and then performed the relocation write there without validating rela.r_offset. Its sibling shared/dynamic branch already rejected out-of-range offsets via llext_file_offset().\n\nrela.r_offset is read directly from the ELF's RELA table, so a crafted entry with an offset larger than the target section makes the write land arbitrarily far outside the extension's text buffer. The result is an attacker-influenced out-of-bounds write (the location via r_offset, the written value being the resolved symbol address) performed in supervisor context at link time, before any extension code runs.\n\nThe path is reached from llext_load() whenever an application loads an attacker-influenced ELF extension on Xtensa with writable storage; llext is documented to accept extensions of untrusted origin. Impact is supervisor-context memory corruption (integrity and availability loss, and a sandbox-boundary escape for user-mode extensions). Exploitation is gated by the Xtensa relocatable PLT path and writable storage, and turning the out-of-range write into a useful primitive is non-trivial.\n\nThe fix adds a bound check rejecting any RELA entry whose r_offset >= tgt->sh_size, mirroring the existing validation in the shared branch."}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": ["subsys/llext/llext_link.c"], "versions": [{"version": "3.7.0", "status": "affected", "versionType": "semver", "lessThan": "4.4.2"}]}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/106540afbd22087ad40b90f53fb22657754a719e", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49", "name": "GHSA-xv9q-6mrf-8j49"}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 6.3, "baseSeverity": "MEDIUM"}}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "bounds", "cweId": "CWE-787", "type": "CWE"}]}], "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-12T12:34:31.991332Z", "id": "CVE-2026-12235", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-12T12:34:55.518Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-12235", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-12T12:34:31.991332Z"}}}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-12T12:34:50.410Z"}}], "cna": {"title": "Out-of-bounds write in Xtensa llext PLT relocation from malformed ELF (CWE-787)", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 6.3, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H"}}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "versions": [{"status": "affected", "version": "3.7.0", "lessThan": "4.4.2", "versionType": "semver"}], "packageName": "zephyr", "programFiles": ["subsys/llext/llext_link.c"], "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected"}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/106540afbd22087ad40b90f53fb22657754a719e", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49", "name": "GHSA-xv9q-6mrf-8j49"}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "The Linkable Loadable Extensions (llext) subsystem mis-handles PLT/RELA relocation entries when linking a relocatable (partially-linked) ELF extension. In llext_link_plt() (subsys/llext/llext_link.c), the relocatable branch (tgt != NULL, the path used for Xtensa relocatable objects) computed the patch address as ext->mem[LLEXT_MEM_TEXT] - text.sh_offset + rela.r_offset + tgt->sh_offset and then performed the relocation write there without validating rela.r_offset. Its sibling shared/dynamic branch already rejected out-of-range offsets via llext_file_offset().\n\nrela.r_offset is read directly from the ELF's RELA table, so a crafted entry with an offset larger than the target section makes the write land arbitrarily far outside the extension's text buffer. The result is an attacker-influenced out-of-bounds write (the location via r_offset, the written value being the resolved symbol address) performed in supervisor context at link time, before any extension code runs.\n\nThe path is reached from llext_load() whenever an application loads an attacker-influenced ELF extension on Xtensa with writable storage; llext is documented to accept extensions of untrusted origin. Impact is supervisor-context memory corruption (integrity and availability loss, and a sandbox-boundary escape for user-mode extensions). Exploitation is gated by the Xtensa relocatable PLT path and writable storage, and turning the out-of-range write into a useful primitive is non-trivial.\n\nThe fix adds a bound check rejecting any RELA entry whose r_offset >= tgt->sh_size, mirroring the existing validation in the shared branch."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "bounds"}]}], "providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-12T04:55:15.620Z"}}}, "cveMetadata": {"cveId": "CVE-2026-12235", "state": "PUBLISHED", "dateUpdated": "2026-08-12T12:34:55.518Z", "dateReserved": "2026-06-15T01:56:05.689Z", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "datePublished": "2026-08-12T04:55:15.620Z", "assignerShortName": "zephyr"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected", "packageName": "zephyr", "product": "zephyr", "programFiles": ["subsys/llext/llext_link.c"], "vendor": "zephyrproject", "versions": [{"lessThan": "4.4.2", "status": "affected", "version": "3.7.0", "versionType": "semver"}]}], "source": "vulnerabilities@zephyrproject.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Linkable Loadable Extensions (llext) subsystem mis-handles PLT/RELA relocation entries when linking a relocatable (partially-linked) ELF extension. In llext_link_plt() (subsys/llext/llext_link.c), the relocatable branch (tgt != NULL, the path used for Xtensa relocatable objects) computed the patch address as ext->mem[LLEXT_MEM_TEXT] - text.sh_offset + rela.r_offset + tgt->sh_offset and then performed the relocation write there without validating rela.r_offset. Its sibling shared/dynamic branch already rejected out-of-range offsets via llext_file_offset().\n\nrela.r_offset is read directly from the ELF's RELA table, so a crafted entry with an offset larger than the target section makes the write land arbitrarily far outside the extension's text buffer. The result is an attacker-influenced out-of-bounds write (the location via r_offset, the written value being the resolved symbol address) performed in supervisor context at link time, before any extension code runs.\n\nThe path is reached from llext_load() whenever an application loads an attacker-influenced ELF extension on Xtensa with writable storage; llext is documented to accept extensions of untrusted origin. Impact is supervisor-context memory corruption (integrity and availability loss, and a sandbox-boundary escape for user-mode extensions). Exploitation is gated by the Xtensa relocatable PLT path and writable storage, and turning the out-of-range write into a useful primitive is non-trivial.\n\nThe fix adds a bound check rejecting any RELA entry whose r_offset >= tgt->sh_size, mirroring the existing validation in the shared branch."}], "id": "CVE-2026-12235", "lastModified": "2026-08-12T13:17:19.377", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.2, "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-12235", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-12T12:34:31.991332Z", "version": "2.0.3"}}]}, "published": "2026-08-12T05:17:42.277", "references": [{"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/commit/106540afbd22087ad40b90f53fb22657754a719e"}, {"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-xv9q-6mrf-8j49"}], "sourceIdentifier": "vulnerabilities@zephyrproject.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}]}

{}

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