CVE-2026-101276

CRITICALPre-NVD 9.29.2—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (31st percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 5 sources updated this week
9.2EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.2Exploit: None knownExposed services: Not assessed

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

iperf3 3.21 (esnet/iperf) contains a remote, unauthenticated heap use-after-free: the server's per-test watchdog server_timer_proc() frees streams without cancelling/joining their worker threads, so a blocked worker dereferences a freed iperf_stream; fixed in 3.22.

CVSS v3
9.2
EG Score
9.2CRITICALmedium confidence
EG Risk
42
EG Risk 42/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity92% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
31st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 30, 2026

Last Modified

October 1, 2026

Advisory Details (1)

Auto-updated Sep 30, 2026
No patch confirmed yet.
generic

esnet/iperf 3.22 on GitHub

https://newreleases.io/project/github/esnet/iperf/release/3.22

Vendor Advisories for CVE-2026-101276(2)

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
iperf33.18-2 ... 3.22-0.1 (9 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
iperf33.18-2 ... 3.22-0.1 (7 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 55× in last 7d / 55× 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. 2026-10-05 06:52 UTCVendor advisory
  2. 2026-10-05 06:52 UTCGHSA enrichment
  3. 2026-10-05 03:08 UTCVendor advisory
  4. 2026-10-05 03:08 UTCGHSA enrichment
  5. 2026-10-04 23:24 UTCEG score recompute
  6. 2026-10-04 23:24 UTCVendor advisory
  7. 2026-10-04 23:24 UTCGHSA enrichment
  8. 2026-10-04 23:21 UTCEPSS rescore
  9. 2026-10-04 19:40 UTCVendor advisory
  10. 2026-10-04 19:40 UTCGHSA enrichment
  11. 2026-10-04 15:56 UTCVendor advisory
  12. 2026-10-04 15:56 UTCGHSA enrichment
  13. 2026-10-04 12:11 UTCVendor advisory
  14. 2026-10-04 12:11 UTCGHSA enrichment
  15. 2026-10-04 08:28 UTCVendor advisory
  16. 2026-10-04 08:28 UTCGHSA enrichment
  17. 2026-10-04 04:43 UTCVendor advisory
  18. 2026-10-04 04:43 UTCGHSA enrichment
  19. 2026-10-04 00:59 UTCVendor advisory
  20. 2026-10-04 00:59 UTCGHSA enrichment
  21. 2026-10-03 21:15 UTCVendor advisory
  22. 2026-10-03 21:15 UTCGHSA enrichment
  23. 2026-10-03 17:31 UTCEG score recompute
  24. 2026-10-03 17:31 UTCVendor advisory
  25. 2026-10-03 17:31 UTCGHSA enrichment
Show 30 more
  1. 2026-10-03 14:25 UTCEPSS rescore
  2. 2026-10-03 13:47 UTCVendor advisory
  3. 2026-10-03 13:47 UTCGHSA enrichment
  4. 2026-10-03 10:00 UTCVendor advisory
  5. 2026-10-03 10:00 UTCGHSA enrichment
  6. 2026-10-03 06:16 UTCGHSA enrichment
  7. 2026-10-03 02:32 UTCGHSA enrichment
  8. 2026-10-02 22:47 UTCGHSA enrichment
  9. 2026-10-02 19:01 UTCEG score recompute
  10. 2026-10-02 19:01 UTCGHSA enrichment
  11. 2026-10-02 15:17 UTCGHSA enrichment
  12. 2026-10-02 11:31 UTCGHSA enrichment
  13. 2026-10-02 07:45 UTCGHSA enrichment
  14. 2026-10-02 03:58 UTCGHSA enrichment
  15. 2026-10-02 00:13 UTCGHSA enrichment
  16. 2026-10-01 20:30 UTCEG score recompute
  17. 2026-10-01 20:29 UTCGHSA enrichment
  18. 2026-10-01 19:49 UTCEPSS rescore
  19. 2026-10-01 16:34 UTCEG score recompute
  20. 2026-10-01 16:34 UTCGHSA enrichment
  21. 2026-10-01 15:56 UTCEG score recompute
  22. 2026-10-01 15:56 UTCGHSA enrichment
  23. 2026-10-01 13:45 UTCGHSA enrichment
  24. 2026-10-01 10:01 UTCGHSA enrichment
  25. 2026-10-01 06:18 UTCGHSA enrichment
  26. 2026-10-01 02:34 UTCGHSA enrichment
  27. 2026-10-01 01:02 UTCEG score recompute
  28. 2026-10-01 01:02 UTCGHSA enrichment
  29. 2026-09-30 21:18 UTCEG score recompute
  30. 2026-09-30 21:15 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-101276?
CVE-2026-101276 is a critical vulnerability published on September 30, 2026. iperf3 3.21 (esnet/iperf) contains a remote, unauthenticated heap use-after-free: the server's per-test watchdog servertimerproc() frees streams without cancelling/joining their worker threads, so a blocked worker dereferences a freed iperf_stream; fixed in 3.22.
When was CVE-2026-101276 disclosed?
CVE-2026-101276 was first published on September 30, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-101276 actively exploited?
CVE-2026-101276 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-101276?
CVE-2026-101276 has a CVSS base score of 9.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-101276?
No fix for CVE-2026-101276 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-2026-101276 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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