CVE-2026-98038

UNRATEDCVSS · not yet scoredTrending — 3 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: Keep refcount_acquire nullable for borrowed RCU kptrs

bpf_refcount_acquire() is fallible for a borrowed reference because the object may have reached a zero refcount. The verifier therefore keeps KF_RET_NULL on the return value unless the argument is an owning reference.

An RCU-protected load of a local kptr is marked MEM_ALLOC, but it only receives NON_OWN_REF when the pointee contains a graph node. A refcounted object without a graph node consequently looks like an owning reference even though the loaded register has no acquired reference state. If the program drops the last real reference while remaining in the RCU critical section, refcount_inc_not_zero() returns NULL while the verifier treats the result as non-NULL.

Only classify the argument as owning when it is backed by a verifier-tracked reference. This retains the non-NULL return for pointers from bpf_obj_new(), bpf_kptr_xchg(), or an earlier successful acquisition, while requiring a NULL check for borrowed RCU kptrs.

[ kkd: Rewrote commit log ]

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
7th
KEV
Not listed

Published

September 25, 2026

Last Modified

September 25, 2026

References (2)

Vendor Advisories for CVE-2026-98038(1)

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

Affected Packages

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (181 versions)
  • every version on: no fix on record
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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 7.2.7-1: fixed in 7.2.7-1
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Data Freshness Timeline

(refreshed 12× in last 7d / 17× 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. 2026-10-04 12:32 UTCGHSA enrichment
  3. 2026-10-03 14:26 UTCEPSS rescore
  4. 2026-10-02 17:57 UTCEPSS rescore
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-10-01 12:12 UTCEG score recompute
  7. 2026-10-01 12:12 UTCGHSA enrichment
  8. 2026-09-30 15:04 UTCEPSS rescore
  9. 2026-09-28 13:52 UTCEPSS rescore
  10. 2026-09-28 13:52 UTCEPSS rescore
  11. 2026-09-28 11:53 UTCEG score recompute
  12. 2026-09-28 11:53 UTCGHSA enrichment
  13. 2026-09-27 13:49 UTCEPSS rescore
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-25 11:30 UTCNVD update
  16. 2026-09-25 10:29 UTCEG score recompute
  17. 2026-09-25 10:27 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-98038?
CVE-2026-98038 is a publicly disclosed vulnerability published on September 25, 2026. In the Linux kernel, the following vulnerability has been resolved: bpf: Keep refcount_acquire nullable for borrowed RCU kptrs bpfrefcountacquire() is fallible for a borrowed reference because the object may have reached a zero refcount. The verifier therefore keeps KFRETNULL on the return value…
When was CVE-2026-98038 disclosed?
CVE-2026-98038 was first published on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-98038 actively exploited?
CVE-2026-98038 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-98038?
No fix for CVE-2026-98038 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-2026-98038 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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