5.5

CVE-2025-21779: linux NULL Pointer Dereference

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-21779DEBIAN-CVE-2025-21779
Published 27-02-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-21779 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.8% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.25%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 33 · Related 32
DLA-4102-1DLA-4178-1SUSE-SU-2025:01600-1SUSE-SU-2025:01919-1SUSE-SU-2025:1177-1SUSE-SU-2025:1178-1

Timeline

  1. 27-02-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Reject Hyper-V's SEND_IPI hypercalls if local APIC isn't in-kernel Advertise support for Hyper-V's SEND_IPI and SEND_IPI_EX hypercalls if and only if the local API is emulated/virtualized by KVM, and explicitly reject said hypercalls if the local APIC is emulated in userspace, i.e. don't rely on userspace to opt-in to KVM_CAP_HYPERV_ENFORCE_CPUID. Rejecting SEND_IPI and SEND_IPI_EX fixes a NULL-pointer dereference if Hyper-V enlightenments are exposed to the guest without an in-kernel local APIC: dump_stack+0xbe/0xfd __kasan_report.cold+0x34/0x84 kasan_report+0x3a/0x50 __apic_accept_irq+0x3a/0x5c0 kvm_hv_send_ipi.isra.0+0x34e/0x820 kvm_hv_hypercall+0x8d9/0x9d0 kvm_emulate_hypercall+0x506/0x7e0 __vmx_handle_exit+0x283/0xb60 vmx_handle_exit+0x1d/0xd0 vcpu_enter_guest+0x16b0/0x24c0 vcpu_run+0xc0/0x550 kvm_arch_vcpu_ioctl_run+0x170/0x6d0 kvm_vcpu_ioctl+0x413/0xb20 __se_sys_ioctl+0x111/0x160 do_syscal1_64+0x30/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Note, checking the sending vCPU is sufficient, as the per-VM irqchip_mode can't be modified after vCPUs are created, i.e. if one vCPU has an in-kernel local APIC, then all vCPUs have an in-kernel local APIC.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

+0.02 pp

From 0.24% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.25%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu133 products
  • linuxAll versions (No fix recorded) | < 5.15.0-140.150 | < 6.8.0-78.78
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1084.91 | < 6.8.0-1035.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < 61224533f2b61e252b03e214195d27d64b22989a | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < 45fa526b0f5a34492ed0536c3cdf88b78380e4de | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < 5393cf22312418262679eaadb130d608c75fe690 | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < 874ff13c73c45ecb38cb82191e8c1d523f0dc81b | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < aca8be4403fb90db7adaf63830e27ebe787a76e8 | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < ca29f58ca374c40a0e69c5306fc5c940a0069074 | ≥ 214ff83d4473a7757fa18a64dc7efe3b0e158486, < a8de7f100bb5989d9c3627d3a223ee1c863f3b69 | 4.20
  • linux_kernel≥ 4.20, < 6.1.129 | ≥ 6.2, < 6.6.79 | ≥ 6.7, < 6.12.16 | ≥ 6.13, < 6.13.4 | 6.14:rc1 | 6.14:rc2
Debian1 product
  • linux< 6.1.129-1 | < 6.12.16-1

3 vendors · 136 products

References

38 links
Show all 38 references