{"cve":"CVE-2025-10543","nvd":{"published":"2025-12-02T09:15:46.127","modified":"2026-10-18T18:10:00.100","status":"Analyzed","description":"In Eclipse Paho Go MQTT v3.1 library (paho.mqtt.golang) versions <=1.5.0 UTF-8 encoded strings, passed into the library, may be incorrectly encoded if their length exceeds 65535 bytes. This may lead to unexpected content in packets sent to the server (for example, part of an MQTT topic may leak into the message body in a PUBLISH packet).\n\n\nThe issue arises because the length of the data passed in was converted from an int64/int32 (depending upon CPU) to an int16 without checks for overflows. The int16 length was then written, followed by the data (e.g. topic). This meant that when the data (e.g. topic) was over 65535 bytes then the amount of data written exceeds what the length field indicates. This could lead to a corrupt packet, or mean that the excess data leaks into another field (e.g. topic leaks into message body).","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-197","CWE-681"],"references":["https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/254"],"products":["eclipse:paho_mqtt"],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-10543","score":0.00227,"percentile":0.13256,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-32fw-gq77-f2f2","url":"https://osv.dev/vulnerability/GHSA-32fw-gq77-f2f2","summary":"Eclipse Paho Go MQTT may incorrectly encode strings if length exceeds 65535 bytes","modified":"2026-09-10T03:50:31.188557268Z","packages":[{"ecosystem":"Go","name":"github.com/eclipse/paho.mqtt.golang","purl":"pkg:golang/github.com/eclipse/paho.mqtt.golang","ranges":["<1.5.1"],"fixed":["1.5.1"]}]},{"id":"GO-2025-4173","url":"https://osv.dev/vulnerability/GO-2025-4173","summary":"Eclipse Paho Go MQTT may incorrectly encode strings if length exceeds 65535 bytes in github.com/eclipse/paho.mqtt.golang","modified":"2026-02-04T03:35:12.277720Z","packages":[{"ecosystem":"Go","name":"github.com/eclipse/paho.mqtt.golang","purl":"pkg:golang/github.com/eclipse/paho.mqtt.golang","ranges":["<1.5.1"],"fixed":["1.5.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}