How severe is CVE-2026-21862?

CVE-2026-21862 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-21862 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21862?

CVE-2026-21862 primarily affects Rustfs. In total, 77 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-21862?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-21862 have an EU (EUVD) identifier?

Yes. CVE-2026-21862 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5219.

When was CVE-2026-21862 published?

CVE-2026-21862 was published on 2026-02-03 and last updated on 2026-06-17.

CVE-2026-21862

CVE-2026-21862 is a high-severity vulnerability in Rustfs with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 7.7
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-5219
Weakness: CWE-290
Affected product: Rustfs
Published: 2026-02-03
Last modified: 2026-06-17

Description

RustFS is a distributed object storage system built in Rust. Prior to version alpha.78, IP-based access control can be bypassed: get_condition_values trusts client-supplied X-Forwarded-For/X-Real-Ip without verifying a trusted proxy, so any reachable client can spoof aws:SourceIp and satisfy IP-allowlist policies. This issue has been patched in version alpha.78.

Frequently asked questions

What is CVE-2026-21862?: RustFS is a distributed object storage system built in Rust. Prior to version alpha.78, IP-based access control can be bypassed: get_condition_values trusts client-supplied X-Forwarded-For/X-Real-Ip without verifying a trusted proxy, so any reachable client can spoof aws:SourceIp and satisfy IP-allowlist policies. This issue has been patched in version alpha.78.
How severe is CVE-2026-21862?: CVE-2026-21862 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-21862 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21862?: CVE-2026-21862 primarily affects Rustfs. In total, 77 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-21862?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-21862 have an EU (EUVD) identifier?: Yes. CVE-2026-21862 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5219.
When was CVE-2026-21862 published?: CVE-2026-21862 was published on 2026-02-03 and last updated on 2026-06-17.

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-fc6g-2gcp-2qrq

Affected products (77)

cpe:2.3:a:rustfs:rustfs:1.0.0:alpha1:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha10:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha11:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha12:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha13:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha14:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha15:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha16:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha17:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha18:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha19:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha2:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha20:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha21:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha22:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha23:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha24:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha25:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha26:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha27:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha28:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha29:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha3:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha30:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha31:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha32:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha33:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha34:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha35:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha36:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha37:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha38:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha39:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha4:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha40:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha41:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha42:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha43:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha44:*:*:*:rust:*:*
cpe:2.3:a:rustfs:rustfs:1.0.0:alpha45:*:*:*:rust:*:*

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