{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-39853 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-39853 is a high-severity memory corruption vulnerability in mtrojnar osslsigncode, published on 9 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-39853 and fix it if it is affected.\n\nWhat it is: CVE-2026-39853 is a high-severity memory corruption vulnerability in mtrojnar osslsigncode, published on 9 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-39853 in the wild and no public exploit code.\n\nAffected product: mtrojnar osslsigncode. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-39853/ (Markdown: https://insights.sbomify.com/CVE-2026-39853/index.md)","id":"CVE-2026-39853","markdown":"https://insights.sbomify.com/CVE-2026-39853/index.md","name":"CVE-2026-39853","record":{"aliases":["DEBIAN-CVE-2026-39853","GHSA-hx87-8754-xvh4","UBUNTU-CVE-2026-39853"],"analysis":{"component_type":"developer_tool","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Authenticode signing tool","requires_auth":"none","summary":"Attackers can execute arbitrary code by tricking users into verifying maliciously crafted signed files with oversized digest fields.","user_interaction":"required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"osslsigncode","vendor":"osslsigncode_project"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"},{"id":"CWE-121","name":"Stack-based Buffer Overflow"}],"description":"osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.12, A stack buffer overflow vulnerability exists in osslsigncode in several signature verification paths. During verification of a PKCS#7 signature, the code copies the digest value from a parsed SpcIndirectDataContent structure into a fixed-size stack buffer  (mdbuf[EVP_MAX_MD_SIZE], 64 bytes) without validating that the source length fits within the destination buffer. This pattern is present in the verification handlers for PE, MSI, CAB, and script files. An attacker can craft a malicious signed file with an oversized digest field in SpcIndirectDataContent. When a user verifies such a file with osslsigncode verify, the unbounded memcpy can overflow the stack buffer and corrupt adjacent stack state. This vulnerability is fixed in 2.12.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification","id":"CVE-2026-39853","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"osslsigncode has an Integer Underflow in PE Page Hash Calculation Can Cause Out-of-Bounds Read","id":"CVE-2026-39855"},"packages":[],"prev":{"headline":"Quarkus authorization bypass via semicolon path normalization inconsistency","id":"CVE-2026-39852"},"products":["osslsigncode"],"published":"2026-04-09","related":[{"cvss_score":9.8,"headline":"Privilege escalation in n/a","id":"CVE-2025-70888","kev_date_added":null,"published":"2026-03-25"},{"cvss_score":7.8,"headline":"Memory corruption in n/a","id":"CVE-2023-36377","kev_date_added":null,"published":"2023-07-03"},{"cvss_score":5.5,"headline":"osslsigncode has an Integer Underflow in PE Page Hash Calculation Can Cause Out-of-Bounds Read","id":"CVE-2026-39855","kev_date_added":null,"published":"2026-04-09"},{"cvss_score":5.5,"headline":"osslsigncode has an Out-of-Bounds Read via Unvalidated Section Bounds in PE Page Hash Calculation","id":"CVE-2026-39856","kev_date_added":null,"published":"2026-04-09"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-04-09","vendors":["mtrojnar"]},"summary":"Attackers can execute arbitrary code by tricking users into verifying maliciously crafted signed files with oversized digest fields.","url":"https://insights.sbomify.com/CVE-2026-39853/"}