Vulnerability in Linux kernel (CVE-2026-98588)
Summary
Vulnerability in Linux kernel (CVE-2026-98588). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc
sock_map_alloc() only rejects max_entries == 0 and otherwise allows any
u32 value. sock_map_free() then walks the sks[] array with a signed int
iterator:
int i;
for (i = 0; i < stab->map.max_entries; i++)
struct sock **psk = &stab->sks[i];
When a SOCKMAP is created with max_entries = 0xffffffff (UINT_MAX), the
allocation of 32 GiB can succeed on large-memory hosts. During free the
counter reaches 0x80000000, wraps to INT_MIN, is sign-extended by movslq
and turned into a ~16 GiB negative offset from stab->sks, pointing far
below the allocation.
The faulting access is an xchg() write in sock_map_free(). Without
KASAN, the same out-of-bounds write can fault on an unmapped vmalloc page
or corrupt an unrelated allocation if that vmalloc address is populated.
On a KASAN kernel with CONFIG_KASAN_VMALLOC=y, the shadow check for that
address hits an unmapped shadow page and oopses first:
BUG: unable to handle page fault for address: fffff521b59c5a00
RIP: 0010:kasan_check_range+0x107/0x190
Call Trace:
sock_map_free+0x93/0x190
map_create+0x68d/0xb30
__sys_bpf+0x21e/0x2e70
Vmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks ==
0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8
exactly at 0xffffc90dace2d000. The same buggy path is reached on the
normal close()/bpf_map_free_deferred() path whenever such a…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-98588 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-98588" on the vendor's site.
CVE-2026-98588 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-98588 linux Fixed in: 6.1.190-1
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com