{"id":"CVE-2026-105958","kind":"vulnerability","aliases":["CVE-2026-105958"],"related":[],"title":"spice-server: client-supplied offsets let a malicious client corrupt heap memory","description":"A flaw was found in spice-server. Multiple migration data handlers use client-supplied offsets from SPICE_MSGC_MIGRATE_DATA messages without bounds validation, allowing a malicious authenticated SPICE client during VM live migration to read arbitrary heap memory or trigger heap corruption via out-of-bounds read and write operations on the message buffer.","summary":"During VM live migration, spice-server trusts offsets sent by a SPICE client in SPICE_MSGC_MIGRATE_DATA messages without checking bounds. A malicious authenticated client can read arbitrary heap memory or corrupt the heap through out-of-bounds reads and writes.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"spice-server","fixed":[],"affected":"all versions (no fixed version published)","ecosystem":"vendor"}],"ecosystems":[],"tags":["infrastructure","kvm","libvirt","live-migration","qemu","rhel","spice","spice-server","virtualization"],"not_affected_if":["no-live-migration","no-spice","vnc-only"],"how_to_check":"Check whether spice-server is installed (rpm -q spice-server or dpkg -l | grep spice) and whether VMs use SPICE graphics with live migration (virsh dumpxml <vm> | grep -i \"graphics type='spice'\"). Compare against distro status; no fixed version exists yet.","fix":"No fixed release published as of 2026-10-25 (Debian unfixed; Red Hat lists RHEL 6/7/8 as affected, no errata). Upstream fix is in spice MR 257 (https://gitlab.freedesktop.org/spice/spice/-/merge_requests/257), release not confirmed. Watch your distro's spice/spice-server package.","status":"open","published_at":"2026-10-16T13:16:53+00:00","first_seen_at":"2026-10-23T21:57:12+00:00","triaged_at":"2026-10-25T03:25:07+00:00","updated_at":"2026-10-25T03:47:59+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-25T03:25:07Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"spice-server: client-supplied offsets let a malicious client corrupt heap memory","impact":"high","summary":"During VM live migration, spice-server trusts offsets sent by a SPICE client in SPICE_MSGC_MIGRATE_DATA messages without checking bounds. A malicious authenticated client can read arbitrary heap memory or corrupt the heap through out-of-bounds reads and writes.","category":"infrastructure","nicknames":[],"who_cares":["spice","virtualization","qemu","libvirt"],"confidence":0.6,"needs_auth":"yes","worst_case":"Attacker reads host heap memory or corrupts heap during live migration","analyst_note":"Sources give only the NVD entry; find the affected spice-server versions and the fixed release in the NVD or upstream spice advisories.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-live-migration"],"who_is_affected":"unknown","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000523,"input_tokens":3313,"output_tokens":383,"severity_before":"high"},"analyst_status":"done","analyst_note":"Sources give only the NVD entry; find the affected spice-server versions and the fixed release in the NVD or upstream spice advisories.","search":"'-105958':17A,20A '-2026':16A,19A 'allow':107C 'arbitrari':66B,119C 'authent':62B,110C 'bound':59B,77B,105C,130C 'buffer':138C 'check':58B 'client':5A,11A,50B,63B,95C,112C 'client-suppli':4A,94C 'corrupt':12A,70B,125C 'cve':15A,18A 'data':55B,91C,102C 'flaw':82C 'found':84C 'handler':92C 'heap':13A,67B,72B,120C,124C 'infrastructur':24B 'kvm':25B 'let':8A 'libvirt':26B 'live':28B,39B,115C 'live-migr':27B 'malici':10A,61B,109C 'memori':14A,68B,121C 'messag':56B,103C,137C 'migrat':29B,40B,54B,90C,101C,116C 'msgc':53B,100C 'multipl':89C 'offset':7A,45B,97C 'oper':134C 'out-of-bound':74B,127C 'qemu':30B 'read':65B,78B,118C,131C 'rhel':31B 'sent':46B 'server':3A,23A,35B,43B,88C 'spice':2A,22A,32B,34B,42B,49B,52B,87C,99C,111C 'spice-serv':1A,33B,41B,86C 'spice-server':21A 'suppli':6A,96C 'trigger':123C 'trust':44B 'use':93C 'valid':106C 'via':126C 'virtual':36B 'vm':38B,114C 'without':57B,104C 'write':80B,133C","nicknames":[],"mitigations":[],"who_affected":"Hosts running QEMU/libvirt VMs with SPICE displays (RHEL 6/7/8, Debian, Alpaquita and similar) that perform live migration while SPICE clients are connected. An attacker needs an authenticated SPICE client connection and must act during migration. Systems that do not use SPICE or never live-migrate can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-16T13:16:53+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secalert@redhat.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-105958","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105958","severity":null,"published_at":"2026-10-16T13:16:53+00:00","modified_at":"2026-10-16T19:23:18+00:00","first_seen_at":"2026-10-23T21:57:12+00:00","fetched_at":"2026-10-23T22:28:55+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-105958:793","url":null,"severity":null,"published_at":"2026-10-25T03:47:59+00:00","modified_at":"2026-10-25T03:47:59+00:00","first_seen_at":"2026-10-25T03:47:59+00:00","fetched_at":"2026-10-25T03:47:59+00:00","note":"Red Hat advisory read: affects spice-server in RHEL 6/7/8 (no fixed version listed); Debian bookworm/trixie/sid 'unfixed' (0.15.1-1, 0.15.2-1, 0.16.0-3). Upstream MR 257 behind Anubis, unreadable, so no upstream fixed release confirmed. No exploitation or PoC found; no social search done (no CVE-named discussion likely). Mitigation from Red Hat text."}],"documents":[{"id":3350,"url":"https://access.redhat.com/security/cve/cve-2026-105958","title":"Red Hat CVE-2026-105958","kind":"advisory","source":"analyst","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":null},{"id":3351,"url":"https://security-tracker.debian.org/tracker/CVE-2026-105958","title":"Debian tracker CVE-2026-105958","kind":"other","source":"analyst","text":null,"published_at":null,"relation":"mentions","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}