{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-5855 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-5855 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-5855 is a high-severity vulnerability in Contiki-NG, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-5855 and fix it if it is affected.\n\nWhat it is: CVE-2026-5855 is a high-severity vulnerability in Contiki-NG, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-5855 in the wild and no public exploit code.\n\nAffected product: Contiki-NG. 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-2026-5855/ (Markdown: https://insights.sbomify.com/CVE-2026-5855/index.md)","id":"CVE-2026-5855","markdown":"https://insights.sbomify.com/CVE-2026-5855/index.md","name":"CVE-2026-5855","record":{"aliases":["GHSA-ch5q-j8ff-mq34"],"analysis":{"component_type":"iot_embedded","fix_type":"patch","impacts":["data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Contiki-NG IoT OS","requires_auth":"none","summary":"Attackers can read adjacent heap memory, including keys, via crafted CoAP packets in Contiki-NG LwM2M TLV parser.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"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","version":"4.0"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"Contiki-NG's LwM2M TLV parser lwm2m_tlv_read() in os/services/lwm2m/lwm2m-tlv.c ignores its caller-supplied buffer length argument and reads up to six bytes from the input buffer with no bounds check. The caller in lwm2m-engine.c iterates while there is at least one byte remaining, so a crafted CoAP WRITE to any LwM2M endpoint whose final TLV supplies exactly one byte triggers up to five out-of-bounds reads of heap memory adjacent to the CoAP input buffer, disclosing memory contents (including key material and peer addresses) through the parsed tlv-\u003eid, tlv-\u003elength, and tlv-\u003evalue fields. Corrupted tlv_len derived from the out-of-bounds memory further corrupts the caller's parse offset. In LwM2M NoSec mode, the default for constrained devices, no authentication is required.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Contiki-NG LwM2M TLV Parser Out-of-Bounds Read via Unchecked Buffer Length in lwm2m_tlv_read","id":"CVE-2026-5855","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"information_disclosure","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Contiki-NG DNS/mDNS Resolver Out-of-Bounds Read via Unchecked skip_name Traversal Before Transaction-ID Validation","id":"CVE-2026-5856"},"packages":[],"prev":{"headline":"Totolink A7100RU CGI cstecgi.cgi setWiFiEasyCfg os command injection","id":"CVE-2026-5854"},"products":["Contiki-NG"],"published":"2026-08-06","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-14","vendors":["Contiki-NG"]},"summary":"Attackers can read adjacent heap memory, including keys, via crafted CoAP packets in Contiki-NG LwM2M TLV parser.","url":"https://insights.sbomify.com/CVE-2026-5855/"}