{"id":"CVE-2026-45712","summary":"Mailpit: Concurrent map read & write in proxy CSS rewriter - remote unauth crash (fatal error: concurrent map read and map write)","details":"Mailpit is an email testing tool and API for developers. Prior to version 1.30.0, the screenshot/print proxy (/proxy?data=…) maintains a package-level assets map[string]MessageAssets cache, but reads the map without holding assetsMutex while a long-running cleanup goroutine and (re-entrant) CSS-rewriting code path concurrently write to it under the lock. When the unsynchronized read coincides with a synchronized write, Go's runtime raises fatal error: concurrent map read and map write — a runtime.throw that is not recoverable by http.Server's handler-panic recover. The whole Mailpit process exits, taking the SMTP, POP3 and HTTP listeners down with it. Version 1.30.0 contains a patch.","aliases":["GHSA-w4vj-r5pg-3722","GO-2026-5689"],"modified":"2026-08-12T03:51:44.993023095Z","published":"2026-07-20T14:59:40.516Z","related":["openSUSE-SU-2026:21483-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45712.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-362","CWE-770"]},"references":[{"type":"WEB","url":"https://github.com/axllent/mailpit/releases/tag/v1.30.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45712.json"},{"type":"ADVISORY","url":"https://github.com/axllent/mailpit/security/advisories/GHSA-w4vj-r5pg-3722"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45712"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/axllent/mailpit","events":[{"introduced":"0"},{"fixed":"af8756a32cf7ecf06bef109c1348b783f1a239ee"}],"database_specific":{"cpe":"cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.30.0"}],"source":["AFFECTED_FIELD","CPE_RANGE","REFERENCES"]}}],"versions":["v1.29.7","v1.29.6","v1.29.5","v1.29.4","v1.29.3","v1.29.2","v1.29.1","v1.29.0","v1.28.4","v1.28.3","v1.28.2","v1.28.1","v1.28.0","v1.27.11","v1.27.10","v1.27.9","v1.27.8","v1.27.7","v1.27.6","v1.27.5","v1.27.4","v1.27.3","v1.27.2","v1.27.1","v1.27.0","v1.26.2","v1.26.1","v1.26.0","v1.25.1","v1.25.0","v1.24.2","v1.24.1","v1.24.0","v1.23.2","v1.23.1","v1.23.0","v1.22.3","v1.22.2","v1.22.1","v1.22.0","v1.21.8","v1.21.7","v1.21.6","v1.21.5","v1.21.4","v1.21.3","v1.21.2","v1.21.1","v1.21.0","v1.20.7","v1.20.6","v1.20.5","v1.20.4","v1.20.3","v1.20.2","v1.20.1","v1.20.0","v1.19.3","v1.19.2","v1.19.1","v1.19.0","v1.18.7","v1.18.6","v1.18.5","v1.18.4","v1.18.3","v1.18.2","v1.18.1","v1.18.0","v1.17.1","v1.17.0","v1.16.0","v1.15.1","v1.15.0","v1.14.4","v1.14.3","v1.14.2","v1.14.1","v1.14.0","v1.13.3","v1.13.2","v1.13.1","v1.13.0","v1.12.1","v1.12.0","v1.11.1","v1.11.0","v1.10.4","v1.10.3","v1.10.2","v1.10.1","v1.10.0","v1.9.10","v1.9.9","v1.9.8","v1.9.7","v1.9.6","v1.9.5","v1.9.4","v1.9.3","v1.9.2","v1.9.1","v1.9.0","v1.8.4","v1.8.3","v1.8.2","v1.8.1","v1.8.0","v1.7.1","v1.7.0","v1.6.22","v1.6.21","v1.6.20","v1.6.19","v1.6.18","v1.6.17","v1.6.16","v1.6.15","v1.6.14","v1.6.13","v1.6.12","v1.6.11","v1.6.10","v1.6.9","v1.6.8","v1.6.7","v1.6.6","v1.6.5","v1.6.4","v1.6.3","v1.6.2","v1.6.1","v1.6.0","v1.5.5","v1.5.4","v1.5.3","v1.5.2","v1.5.1","v1.5.0","v1.4.0","v1.3.11","v1.3.10","v1.3.9","v1.3.8","v1.3.7","v1.3.6","v1.3.5","v1.3.4","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.9","v1.2.8","v1.2.7","v1.2.6","1.2.5","1.2.4","1.2.3","1.2.2","1.2.1","1.2.0","1.1.7"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45712.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}