CVE-2026-42882: oxyno-zeta/s3-proxy is an aws s3 proxy written in go

Q: How do I fix CVE-2026-42882?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Q: Is CVE-2026-42882 being exploited?

CVE-2026-42882 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-42882 affect?

CVE-2026-42882 affects affected software. Severity is critical (CVSS 9.4). oxyno-zeta/s3-proxy is an aws s3 proxy written in go. Prior to 5.0.0, s3-proxy contains an authentication bypass caused by inconsistent URL path interpretation between the authentication middleware and the bucket handler. The authentication

Q: How urgent is CVE-2026-42882?

Priority 60/100. Critical severity; CISA SSVC: public proof of concept; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.4REMOTEWATCHLIST

CVE-2026-42882 is a critical-severity flaw (CVSS 9.4) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

oxyno-zeta/s3-proxy is an aws s3 proxy written in go. Prior to 5.0.0, s3-proxy contains an authentication bypass caused by inconsistent URL path interpretation between the authentication middleware and the bucket handler. The authentication middleware evaluates resource path patterns against the percent-encoded request URI (r.URL.RequestURI()), while the bucket handler constructs S3 object keys from the decoded path (r.URL.Path). This mismatch, c

Why this priority

Critical severity
CISA SSVC: public proof of concept
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.4 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-22, CWE-863
Published	2026-05-11
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-05-11 20:25 UTCPublished CVE record published
2026-10-26 18:10 UTCUpdated Record last modified

Exact fixes by distribution

Go · github.com/oxyno-zeta/s3-proxy · FIXED · 0.0.0-20260424211602-1320e4abd46a · vulnerable: < 0.0.0-20260424211602-1320e4abd46a · source

go get github.com/oxyno-zeta/s3-proxy@v0.0.0-20260424211602-1320e4abd46a go list -m github.com/oxyno-zeta/s3-proxy

Fedora 46 · fzssh · FIXED · 1.4.0-2.fc46 · FEDORA-2026-8004fcd067 · source

sudo dnf upgrade --advisory=FEDORA-2026-8004fcd067

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2026-42882?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-42882 being exploited?

CVE-2026-42882 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-2026-42882 affect?

CVE-2026-42882 affects affected software. Severity is critical (CVSS 9.4). oxyno-zeta/s3-proxy is an aws s3 proxy written in go. Prior to 5.0.0, s3-proxy contains an authentication bypass caused by inconsistent URL path interpretation between the authentication middleware and the bucket handler. The authentication

How urgent is CVE-2026-42882?

Priority 60/100. Critical severity; CISA SSVC: public proof of concept; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

AWS vulnerabilities

References

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