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Full vulnerability report · 2026
CVE-2026-5223High confidence

Crates in third party registries can override the cached source of other crates

Rust Project · Cargo

6.5MediumCVSS 4.0
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.41% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Rust Project Cargo and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

24 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 4 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainrustVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.91.1-r2Alpine Security Database ↗Source updated 6 Oct 2026
Debian trixietrixie · sourcerust-cargoAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 7 Oct 2026
Debian trixietrixie · sourcerustcVendor fix publishedDebian records a fixed source-package version for this release.1.85.1+dfsg1-1+deb13u1Debian Security Tracker ↗Source updated 7 Oct 2026
Debian bookwormbookworm · sourcecargoAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 7 Oct 2026
Debian bookwormbookworm · sourcerust-cargoAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 7 Oct 2026
Debian bookwormbookworm · sourcerustcAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 7 Oct 2026
Debian forkyforky · sourcerust-cargoVendor fix publishedDebian records a fixed source-package version for this release.0.91.0-3Debian Security Tracker ↗Source updated 7 Oct 2026
Debian forkyforky · sourcerustcVendor fix publishedDebian records a fixed source-package version for this release.1.95.0+dfsg1-2Debian Security Tracker ↗Source updated 7 Oct 2026
Debian sidsid · sourcerust-cargoVendor fix publishedDebian records a fixed source-package version for this release.0.91.0-3Debian Security Tracker ↗Source updated 7 Oct 2026
Debian sidsid · sourcerustcVendor fix publishedDebian records a fixed source-package version for this release.1.95.0+dfsg1-2Debian Security Tracker ↗Source updated 7 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustcUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.74Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.76Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.77Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.78Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.79Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.80Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.81Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.82Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.83Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.84Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.85Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.89Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archiverustc-1.91Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical Ubuntu Security ↗Source updated 6 Oct 2026
Open-source package ranges1 source-attributed range

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
rustcargo< 0.97.00.97.0GitHub advisory ↗upstream repository advisory · 26 Jun 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-31658

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

Cargo incorrectly handled symlinks inside of crate tarballs downloaded from third-party registries, allowing a malicious crate to override the source code of another crate from the same registry. The severity of the vulnerability is **medium** for users of third-party registries. Users of crates.io are **not affected**, as crates.io forbids uploading crates containing any symlink.

What

Cargo incorrectly handled symlinks inside of crate tarballs downloaded from third-party registries, allowing a malicious crate to override the source code of another crate from the same registry. The severity of the vulnerability is **medium** for users of third-party registries. Users of crates.io are **not affected**, as crates.io forbids uploading crates containing any symlink.

Why

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

How

An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Cargo incorrectly handled symlinks inside of crate tarballs downloaded from third-party registries, allowing a malicious crate to override the source code of another crate from the same registry. The severity of the vulnerability is **medium** for users of third-party registries. Users of crates.io are **not affected**, as crates.io forbids uploading crates containing any symlink.

Why

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

How

An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → UNIX Symbolic Link (Symlink) Following → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
Passive interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-61 ↗

CWE-61: UNIX Symbolic Link (Symlink) Following. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VILowVulnerable-system integrity: A successful attack can cause a limited loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SAHighSubsequent-system availability: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-61
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

JVN iPedia · Japanese · JVNDB-2026-017907The Rust Programming LanguageのCargoにおける認可判断のための非正規化 URL パスの使用に関する脆弱性

Cargoのバージョン1.68から1.96の間では、スパースインデックスプロトコルを使用するサードパーティレジストリのURLが誤って正規化されていました。ホスティングプロバイダーが同一ドメイン内で任意の名前の複数のレジストリをホストすることを許可している場合、攻撃者はクレートを公開することで同じレジストリの他のユーザーの資格情報を取得できる可能性があります。この脆弱性の深刻度は、攻撃を達成するために必要な非常に限定的な条件があるため、低いと評価されています。

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-017906The Rust Programming LanguageのCargoにおけるUNIX Symbolic Link のフォローに関する脆弱性

Cargoはサードパーティのレジストリからダウンロードしたクレートのtarball内のシンボリックリンクを誤って処理しており、悪意のあるクレートが同じレジストリ内の他のクレートのソースコードを上書きできる可能性がありました。この脆弱性の深刻度はサードパーティのレジストリのユーザーにとって中程度です。crates.ioのユーザーには影響がありません。crates.ioではシンボリックリンクを含むクレートのアップロードを禁止しているためです。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Cargo: 1.0.0 < 1.96.0
Fixed
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 25 May 2026 · Last source change 27 May 2026, 18:35 UTC · CWE-61 · UNIX Symbolic Link (Symlink) Following

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-31658
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-5223 · cve.blacktree.nl