{"answers":{"affected":"2 open source packages ship an affected version, including msgpack. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54522 exists.","fix":"Upgrade msgpack to 1.8.2 or later.","what":"CVE-2026-54522 is a low-severity use after free vulnerability in msgpack-ruby, published on 30 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-54522 and fix it if it is affected.\n\nWhat it is: CVE-2026-54522 is a low-severity use after free vulnerability in msgpack-ruby, published on 30 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54522 exists.\n\nAffected packages and fixed versions:\n- msgpack (RubyGems): affected all versions; fixed in 1.8.2\n- msgpack (RubyGems): affected all versions; fixed in 1.8.2\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-2026-54522/ (Markdown: https://insights.sbomify.com/CVE-2026-54522/index.md)","id":"CVE-2026-54522","markdown":"https://insights.sbomify.com/CVE-2026-54522/index.md","name":"CVE-2026-54522","record":{"aliases":["AZL-109539","AZL-94449","CLEANSTART-2026-ES40374","DEBIAN-CVE-2026-54522","GHSA-4mrv-5p47-p938","MINI-274c-6h97-qvmp","MINI-3p2f-gpjq-4gp2","MINI-43q9-rg3j-g4vp","MINI-65ph-2qvj-gq8f","MINI-7f3f-3vfh-9ghx","MINI-7gpg-3ffp-chpx","MINI-7h25-98x6-5qxp","MINI-7j7h-4896-2gqj","MINI-83gc-h2pf-5m92","MINI-83v5-xp8p-r69c","MINI-8q95-g397-g6f4","MINI-942c-94x9-73p2","MINI-978c-hfhr-h6rj","MINI-c2pp-f9x7-xv84","MINI-gmqh-x47v-p73q","MINI-q8h7-ggg9-67rv","MINI-wx7v-j52p-x47m","OESA-2026-3219","OESA-2026-3220","OESA-2026-3221","UBUNTU-CVE-2026-54522"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","data_modify"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Ruby MessagePack library","requires_auth":"none","summary":"A use-after-free in MessagePack for Ruby allows attackers to disclose or corrupt data across buffers via stale memory references.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"messagepack","vendor":"msgpack"}],"cvss":{"score":2.1,"severity":"low","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"MessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Buffer#clear in ext/msgpack/buffer.c leaves rmem_last, rmem_end, and rmem_owner stale after _msgpack_buffer_shift_chunk returns an rmem page to the shared pool, allowing a subsequent Buffer#write and a second MessagePack::Buffer to alias the page and disclose or corrupt cross-buffer data. This issue is fixed in version 1.8.2.","ecosystems":["RubyGems"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"MessagePack::Buffer#clear Use-After-Free that Enables Cross-Buffer Disclosure","id":"CVE-2026-54522","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"RubyGems","product":null,"products":[],"type":"use_after_free","year":"2026"},"n_packages":2,"n_references":2,"next":{"headline":"Kyverno's NamespacedGeneratingPolicy generator.apply() namespace argument unvalidated -- background controller creates RoleBindings in any namespace including kube-system","id":"CVE-2026-54523"},"packages":[{"ecosystem":"RubyGems","fixed":["1.8.2"],"introduced":["0"],"last_affected":[],"package":"msgpack","purl":null,"source":"GHSA-4mrv-5p47-p938"},{"ecosystem":"RubyGems","fixed":["1.8.2"],"introduced":["0"],"last_affected":[],"package":"msgpack","purl":"pkg:gem/msgpack","source":"GHSA-4mrv-5p47-p938"}],"prev":{"headline":"FairEmail: Cross-site scripting (XSS) in AMP message rendering (ActivityAMP)","id":"CVE-2026-54521"},"products":["msgpack-ruby"],"published":"2026-07-30","related":[{"cvss_score":7.5,"headline":"MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error","id":"CVE-2026-57585","kev_date_added":null,"published":"2026-06-30"},{"cvss_score":7.5,"headline":"MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation","id":"CVE-2026-21452","kev_date_added":null,"published":"2026-01-02"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"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":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-30","vendors":["msgpack"]},"summary":"A use-after-free in MessagePack for Ruby allows attackers to disclose or corrupt data across buffers via stale memory references.","url":"https://insights.sbomify.com/CVE-2026-54522/"}