CVE-2026-89923KVM: s390: Free guest debug data on vcpu destroy
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Free guest debug data on vcpu destroy kvm_s390_clear_bp_data() is only called from kvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or disables debugging. A vCPU that is destroyed while hardware breakpoints are still armed - the normal case when the VMM just exits or crashes - leaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM frees the vCPU right after kvm_arch_vcpu_destroy(). That is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but it is unbounded over VM lifetimes. The allocations are GFP_KERNEL_ACCOUNT, so the charge also outlives the exiting process and pins dying memcgs. Fix by clearing the debug data on vCPU destruction. Calling it unconditionally is fine: struct kvm_vcpu is zero allocated, so for a vCPU that never enabled debugging the counters are 0 and the pointers NULL.
Timeline
ID reserved
By Linux
- 5 days later
· 5 days later
Published
- 33 days later
· 33 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < 053f2068cf9b0654b651fed5ad7649d3deb982bf
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < 6c996b12bbe4a6023076e8eee3cfaf2cc99db76c
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < d6280fc540d8f4653c9b54a78cb747e128070f5e
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < 544a5a665019cef394ce8bda97fa7a2cab253781
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < 9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < b5acacfdb8966abff91836c1c5bd7da59d8a526e
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < e4d8b7f176b976474e0800ba71ee2dfa3ce263c9
- affected 27291e2165b6de70c476b7b675308113edd69a60 – < e7f698b09d4a7c36b299acf680fc50fe868e2bcd
- affected 3.16
- unaffected < 3.16
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.110 – ≤ 6.12.*
- unaffected 6.18.51 – ≤ 6.18.*
- unaffected 7.2.5 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/053f2068cf9b0654b651fed5ad7649d3deb982bf (opens in a new tab)
- https://git.kernel.org/stable/c/6c996b12bbe4a6023076e8eee3cfaf2cc99db76c (opens in a new tab)
- https://git.kernel.org/stable/c/d6280fc540d8f4653c9b54a78cb747e128070f5e (opens in a new tab)
- https://git.kernel.org/stable/c/544a5a665019cef394ce8bda97fa7a2cab253781 (opens in a new tab)
- https://git.kernel.org/stable/c/9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63 (opens in a new tab)
- https://git.kernel.org/stable/c/b5acacfdb8966abff91836c1c5bd7da59d8a526e (opens in a new tab)
- https://git.kernel.org/stable/c/e4d8b7f176b976474e0800ba71ee2dfa3ce263c9 (opens in a new tab)
- https://git.kernel.org/stable/c/e7f698b09d4a7c36b299acf680fc50fe868e2bcd (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-80523 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-89923)Record last updated .