Affects the Linux kernel iSCSI target (core infrastructure). Remote exploit can crash or corrupt kernels across many deployments; high-impact for enterprises and infra.
CVE-2026-63888
Linux iSCSI target CRC overread and double-free causing kernel memory corruption.
Is CVE-2026-63888 being exploited?
Not confirmed. CVE-2026-63888 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.78% probability of exploitation in the next 30 days.
How severe is CVE-2026-63888?
CVE-2026-63888 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-63888?
Yes. A fix has been recorded for CVE-2026-63888. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63888 affect?
CVE-2026-63888 affects Linux kernel (LIO iSCSI target / iscsit), Distros with iscsi-target/iscsit enabled. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63888?
Apply kernel/security updates immediately; restrict or block untrusted iSCSI initiators.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote iSCSI initiator can send crafted Text PDUs to trigger CRC OOB read and double-free, causing kernel memory corruption, crash (DoS) and potential privilege escalation.
Immediate action required
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < f7948af0dd03de84079dcd4dc215a69fd6fbb95d
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < badf178b76b0690851df00f4ca9cf2eb8eb0f963
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < 6e22a1cdcc8277af4acc43710577157b77a02c5d
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < d3e9b79aa794f7a23e82de4d710e7d2df610e349
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < ec9f19d52074a191ed1756ed4a7d39fff1a2085c
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < 89c81d1228c00fa6dd91de6c1c5aa1ef8a7875e3
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < 5118ea225fe63b44207ba88047e4866e1ea43812
- affected>= e48354ce078c079996f89d715dfa44814b4eba01 and < 778c2ab142c625a8a8afa570e0f9b7873f445d99
- affected3.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.