oras-go: credential forwarding via unvalidated Location header in blob upload

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

oras-go is a Go library for managing OCI artifacts. Prior to 2.6.1, registry/remote/repository.go in blobStore.completePushAfterInitialPost follows a registry-controlled Location header during monolithic blob upload and reuses the Authorization header from the initial POST request for the subsequent PUT request, allowing a malicious registry to return a cross-host Location and receive the caller's credentials at an attacker-controlled endpoint. This issue is fixed in version 2.6.1.

Source published

17 Jul 2026 19:41:11 UTC

Source modified

20 Jul 2026 13:52:07 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

oras-go is a Go library for managing OCI artifacts. Prior to 2.6.1, registry/remote/repository.go in blobStore.completePushAfterInitialPost follows a registry-controlled Location header during monolithic blob upload and reuses the Authorization header from the initial POST request for the subsequent PUT request, allowing a malicious registry to return a cross-host Location and receive the caller's credentials at an attacker-controlled endpoint. This issue is fixed in version 2.6.1.

Source published

17 Jul 2026 20:17:23 UTC

Source modified

24 Oct 2026 20:10:00 UTC

Observed here

25 Oct 2026 12:17:38 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

## Summary oras-go follows a registry-controlled `Location` header during the monolithic blob upload flow and reuses the `Authorization` header from the initial `POST` request for the subsequent `PUT` request. If a malicious registry returns a cross-host `Location`, oras-go can send the caller's credentials to an attacker-controlled endpoint. ## Affected Versions tested: v2.6.0 (commit 03243809936cce826494b5506f724c6dc11115b1, as-of 2026-01-24) range: unknown; likely affects earlier v2.x releases that include the same upload flow ## Impact Credential leak to an attacker-controlled endpoint and client-side ssrf to a cross-host target. ## Affected Component - `registry/remote/repository.go:878-916` (`blobStore.completePushAfterInitialPost`) ## Reproduction Attachments include `poc.zip` with a local-only harness (no real registry required). It runs a fake registry server that returns a cross-host `Location` and a second server that records whether it received `Authorization`. ```bash unzip -q -o poc.zip -d /tmp/poc cd /tmp/poc/poc-F-ORAS-LOCATION-UPLOAD-001 make canonical make control ``` ## Recommended Fix - validate `Location` before uploading (scheme + hostname + effective port) against the original request, or require an explicit opt-in allowlist for cross-host upload urls - never forward `Authorization` when the upload target changes host or scheme ## references - security policy: https://github.com/oras-project/oras-go/security/policy - vulnerable code: `registry/remote/repository.go` (see `blobStore.completePushAfterInitialPost`)

Source published

1 Jul 2026 21:35:45 UTC

Source modified

10 Sep 2026 03:50:52 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Publisher rating · HIGH

Oras-go: Blob upload vulnerable to credential forwarding via unvalidated Location header in oras.land/oras-go

Source published

24 Jul 2026 18:35:55 UTC

Source modified

24 Jul 2026 19:00:26 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.