CVE-2026-97420

UNRATEDCVSS · not yet scoredTrending — 6 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

In the Linux kernel, the following vulnerability has been resolved:

bpf: NUL-terminate replaced sysctl value

When writing to sysctls, proc_sys_call_handler() guarantees that the buffer passed to proc handlers is NUL-terminated. If bpf_sysctl_set_new_value() replaces the pending sysctl value, it can hand a replacement buffer directly to proc handlers. However, the helper currently copies only buf_len bytes into that buffer without appending a NUL terminator, leaving downstream parsers vulnerable to out-of-bounds access.

Fix this by appending a '\0' after the replaced value to restore the expected sysctl semantics. Since the helper already rejects buf_len greater than PAGE_SIZE - 1, there is always room for the extra byte.

Reproduced in a QEMU x86_64 guest booted with KASAN while exercising the sysctl replacement path with a cgroup/sysctl BPF program. The reproducer targets /proc/sys/net/core/flow_limit_cpu_bitmap, fills the original user write buffer with non-zero bytes, and overrides the sysctl value so the replacement buffer lacks a terminating NUL. Under that setup, the pre-fix kernel reported:

BUG: KASAN: slab-out-of-bounds in strnchrnul+0x72/0x90 Read of size 1 at addr ffff88800de57000 by task repro_patch3/66 CPU: 0 UID: 0 PID: 66 Comm: repro_patch3 Not tainted 7.1.0-rc3-00269-g8370ca1f87cc #6 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x68/0xa0 print_report+0xcb/0x5e0 ? __virt_addr_valid+0x21d/0x3f0 ? strnchrnul+0x72/0x90 ? strnchrnul+0x72/0x90 kasan_report+0xca/0x100 ? strnchrnul+0x72/0x90 strnchrnul+0x72/0x90 bitmap_parse+0x37/0x2e0 flow_limit_cpu_sysctl+0xc6/0x840 ? __pfx_flow_limit_cpu_sysctl+0x10/0x10 ? __kvmalloc_node_noprof+0x5ba/0x870 proc_sys_call_handler+0x31d/0x480 ? __pfx_proc_sys_call_handler+0x10/0x10 ? selinux_file_permission+0x39f/0x500 ? lock_is_held_type+0x9e/0x120 vfs_write+0x98e/0x1000 ... The buggy address is located 0 bytes to the right of allocated 4096-byte region [ffff88800de56000, ffff88800de57000) With this fix applied, rerunning the same sysctl-targeted path yields no corresponding KASAN reports.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.2%
EPSS %ILE
6th
KEV
Not listed

Published

September 24, 2026

Last Modified

October 3, 2026

References (7)

Vendor Advisories for CVE-2026-97420(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
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linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
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Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
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Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (179 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
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Data Freshness Timeline

(refreshed 17× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 23:23 UTCEPSS rescore
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-03 11:31 UTCVendor advisory
  4. 2026-10-03 11:31 UTCGHSA enrichment
  5. 2026-10-03 11:26 UTCNVD update
  6. 2026-10-03 11:10 UTCMITRE cvelistV5
  7. 2026-10-02 17:57 UTCEPSS rescore
  8. 2026-10-02 00:03 UTCEG score recompute
  9. 2026-10-02 00:03 UTCVendor advisory
  10. 2026-10-02 00:03 UTCGHSA enrichment
  11. 2026-10-01 19:51 UTCEPSS rescore
  12. 2026-09-30 15:04 UTCEPSS rescore
  13. 2026-09-28 18:14 UTCEG score recompute
  14. 2026-09-28 18:14 UTCVendor advisory
  15. 2026-09-28 18:13 UTCGHSA enrichment
  16. 2026-09-28 13:52 UTCEPSS rescore
  17. 2026-09-28 13:52 UTCEPSS rescore
  18. 2026-09-27 13:49 UTCEPSS rescore
  19. 2026-09-26 15:59 UTCEPSS rescore
  20. 2026-09-25 13:21 UTCGHSA enrichment
  21. 2026-09-25 13:18 UTCNVD update
  22. 2026-09-25 12:55 UTCGHSA enrichment
  23. 2026-09-25 12:54 UTCMITRE cvelistV5
  24. 2026-09-24 17:33 UTCNVD update
  25. 2026-09-24 16:29 UTCEG score recompute
Show 1 more
  1. 2026-09-24 16:26 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-97420?
CVE-2026-97420 is a publicly disclosed vulnerability published on September 24, 2026. In the Linux kernel, the following vulnerability has been resolved: bpf: NUL-terminate replaced sysctl value When writing to sysctls, procsyscall_handler() guarantees that the buffer passed to proc handlers is NUL-terminated. If bpfsysctlsetnewvalue() replaces the pending sysctl value, it can hand…
When was CVE-2026-97420 disclosed?
CVE-2026-97420 was first published on September 24, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-97420 actively exploited?
CVE-2026-97420 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-97420?
No fix for CVE-2026-97420 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-97420 are linked in the Vendor Advisories panel on this page.

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