PatchTheCVECVE-2026-101283: iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA bu
CVE-2026-101283 is a critical-severity flaw (CVSS 9.2) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA buffer is BIO_read with the attacker-controlled ciphertext length (guard warns only), so an unauthenticated client overflows the heap via an oversized authtoken; fixed in 3.22
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 9.2 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 68%) |
| CISA exploited list | No |
| Weakness | CWE-122 |
| Published | 2026-09-30 |
| Last modified | 2026-10-01 |
Last updated 2026-10-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Official advisories
- Amazon Linux 2023 ALAS: ALAS2023-2026-3299 (medium): iperf3 2026-10-24
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-101283?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-101283 being exploited?
CVE-2026-101283 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-101283 affect?
CVE-2026-101283 affects affected software. Severity is critical (CVSS 9.2). iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA buffer is BIO_read with the attacker-controlled ciphertext length (guard warns only), so an unauthenticated client overflows the hea
How urgent is CVE-2026-101283?
Priority 45/100. Critical severity; Remotely exploitable, no login, no user action