{"id":"CVE-2026-63201","title":"netopeer2-server logging has format string vulnerability via subtree filter","summary":"Netopeer2 is a server for implementing network configuration management based on the `NETCONF` Protocol. In affected versions, a low-privileged authenticated `NETCONF` user can remotely crash `netopeer2-server` by sending a `get RPC` wit…","severity":"high","cvss":7.1,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-134"],"vendor":"CESNET","product":"netopeer2","affected":["netopeer2 < 2.8.21"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-02T17:03:24.936130Z"},"published":"2026-10-30","updated":"2026-11-02","sourceUpdated":"2026-11-02T18:08:38.871Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63201","references":[{"url":"https://github.com/CESNET/netopeer2/security/advisories/GHSA-25gm-4x89-7r2q","label":"https://github.com/CESNET/netopeer2/security/advisories/GHSA-25gm-4x89-7r2q"},{"url":"https://github.com/CESNET/netopeer2/commit/e98beb2d4d8cc82875208bccb8e1348a8e9e95b3","label":"https://github.com/CESNET/netopeer2/commit/e98beb2d4d8cc82875208bccb8e1348a8e9e95b3"},{"url":"https://github.com/CESNET/netopeer2/releases/tag/2.8.21","label":"https://github.com/CESNET/netopeer2/releases/tag/2.8.21"}],"tags":["cve.org"],"epss":0.00432,"epssPercentile":0.37774,"ingestedAt":"2026-11-05T19:30:42.765Z","slug":"CVE-2026-63201","body":"## Overview\n\nNetopeer2 is a server for implementing network configuration management based on the `NETCONF` Protocol. In affected versions, a low-privileged authenticated `NETCONF` user can remotely crash `netopeer2-server` by sending a `get RPC` with an invalid `subtree filter` whose text contains format specifiers. In `src/netconf.c`, `np2srv_rpc_get_cb()` sends the invalid value through `ERR()` to `np2log_printf()`, where `vsnprintf()` first formats the message safely. In `src/log.c`, that already formatted buffer is subsequently passed to `np2log()` as the format string itself, causing `vsyslog()` to interpret attacker-controlled percent sequences and read invalid pointer arguments. The reported denial of service was confirmed on version 2.8.7 using `NETCONF`-over-SSH and AddressSanitizer; reliable remote code execution was not confirmed. `The advisory identifies 2.8.8 as patched`; repository comparisons verify the fix in public release 2.8.21. The affected/fixed boundary remains unresolved because no public 2.8.8 tag was located, which does not establish the status of an untagged 2.8.8 build.\n\n## Affected\n\n- `netopeer2 < 2.8.21`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}