Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.14% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-33244High confidence
React Router has stored XSS via unescaped Location header in prerendered redirect HTML
remix-run · react-router
Official source article: GitHub GHSA-F22V-GFQF-P8F3 ↗. Check the applicable product and release in the original source.
5.4MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium 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 174 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
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
- Confirm that the asset runs remix-run react-router and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 174 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 174 affected or under-investigation product states without a fixed product state in the same current advisory
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 package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| npmreact-router | >= 7.5.1, < 7.13.2 | 7.13.2 | GitHub advisory ↗upstream repository advisory · 8 Sep 2026 |
Direct vendor intelligence
2 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2026-33244 · CSAF 2.0 · revision 5 · interimSUSE Product Security TeamCVE-2026-33244
The vendor explicitly identifies these products as affected by this CVE.
- golang-github-prometheus-prometheus as component of SUSE Linux Enterprise Server 16.0
- golang-github-prometheus-prometheus as component of SUSE Linux Enterprise Server for SAP applications 16.0
- golang-github-prometheus-prometheus as component of openSUSE Leap 16.0
- Summary
- React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (` `) or Data Mode (`createBrowserRouter/ `). This is patched in version 7.13.2.
- Remediation
- To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
CVE-2026-33244 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityreact-router: React Router: Cross-Site Scripting (XSS) via improper HTTP Location header neutralization
The vendor explicitly identifies these products as affected by this CVE.
- cryostat-openshift-console-plugin-npm as a component of Cryostat 4
- grafana-infinity-datasource-npm as a component of Cryostat 4
- react-router as a component of Cryostat 4
- exploit-intelligence-tech-preview/agent-client-rhel9 as a component of Exploit Intelligence
- gatekeeper/gatekeeper-rhel9 as a component of Gatekeeper 3
- mta/mta-ui-rhel8 as a component of Migration Toolkit for Applications 8
- mta/mta-ui-rhel9 as a component of Migration Toolkit for Applications 8
- rhmtc/openshift-migration-ui-rhel8 as a component of Migration Toolkit for Containers
- migration-toolkit-virtualization/mtv-console-plugin-rhel9 as a component of Migration Toolkit for Virtualization
- mtv-candidate/mtv-console-plugin-rhel9 as a component of Migration Toolkit for Virtualization
- multicluster-engine/console-mce-rhel9 as a component of Multicluster Engine for Kubernetes
- network-observability/network-observability-console-plugin-compat-rhel9 as a component of Network Observability Operator
- Summary
- A flaw was found in react-router. When using Framework Mode with pre-rendering enabled, an attacker can exploit improper handling of the HTTP `Location` header value. This can lead to Cross-Site Scripting (XSS), allowing malicious scripts to be injected into statically generated HTML files if the redirect location originates from an untrusted source.
- Remediation
- To mitigate this issue, Red Hat customers should ensure that applications utilizing React Router avoid Framework Mode with pre-rendering enabled, particularly when handling redirect locations from untrusted sources. If this mode is essential, strict validation and sanitization of all input used in redirect URLs are required. Applications configured with Declarative Mode (` `) or Data Mode (`createBrowserRouter/ `) are not susceptible to this flaw.
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 174 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.
What
React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through a network path may attempt exploitation with low privileges. 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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-79 ↗
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NCommon Vulnerability Scoring System 3.1: 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.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.- 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.
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
- 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 2 Jun 2026 · Last source change 2 Jun 2026, 17:28 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-33986
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Remediation statusRemediation status changed from Awaiting fix to Mitigation available.SUSE Product Security Team ↗
- Before
- Awaiting fix
- After
- Mitigation available
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.