Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.28% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-106106High confidence
Quasar Framework: SSR/SSG dev error page discloses the full shell environment and its </script> escape is bypassable
quasarframework · quasar
Official source article: GitHub GHSA-R5MF-4R5X-Q78F ↗. Check the applicable product and release in the original source.
7.1HighCVSS 4.0
Within 7 days
Fix not verifiedHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Restrict local access and enforce least privilege on affected hosts.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs quasarframework quasar and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0, renderSSRError() in utils/render-ssr-error/src/index.js used diagnostic data from utils/render-ssr-error/src/env.js to serialize process.env, request headers, and cookies into the HTTP page returned by serve.devError(), while the development server listened on all interfaces by default. Any network-adjacent client that reaches an SSR or SSG render failure through this development-only error path can obtain shell environment secrets. The renderer escaped only one exact lowercase script closing-tag spelling, so case variants and valid closing-tag delimiter variants in reflected diagnostic data could terminate the script element and inject markup; executing the injected code in a developer browser additionally requires the payload to accompany that developer's request. This issue is fixed in @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0.
What
Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0, renderSSRError() in utils/render-ssr-error/src/index.js used diagnostic data from utils/render-ssr-error/src/env.js to serialize process.env, request headers, and cookies into the HTTP page returned by serve.devError(), while the development server listened on all interfaces by default. Any network-adjacent client that reaches an SSR or SSG render failure through this development-only error path can obtain shell environment secrets. The renderer escaped only one exact lowercase script closing-tag spelling, so case variants and valid closing-tag delimiter variants in reflected diagnostic data could terminate the script element and inject markup; executing the injected code in a developer browser additionally requires the payload to accompany that developer's request. This issue is fixed in @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through an adjacent network 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
Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0, renderSSRError() in utils/render-ssr-error/src/index.js used diagnostic data from utils/render-ssr-error/src/env.js to serialize process.env, request headers, and cookies into the HTTP page returned by serve.devError(), while the development server listened on all interfaces by default. Any network-adjacent client that reaches an SSR or SSG render failure through this development-only error path can obtain shell environment secrets. The renderer escaped only one exact lowercase script closing-tag spelling, so case variants and valid closing-tag delimiter variants in reflected diagnostic data could terminate the script element and inject markup; executing the injected code in a developer browser additionally requires the payload to accompany that developer's request. This issue is fixed in @quasar/render-ssr-error 2.2.4 and @quasar/app-vite 3.3.0.
Why
Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.
How
An attacker operating through an adjacent network 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 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 Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
- Likely attack path
- an adjacent network → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Adjacent
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Passive interaction required
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Not a CVSS 4.0 base metric
- 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:4.0/AV:A/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:H/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.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.SANoneSubsequent-system availability: 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 not verified
- Affected
- quasar: < 2.23.3
- render-ssr-error: < 2.2.4
- app-vite: < 3.3.0
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 6 Oct 2026 · Last source change 6 Oct 2026, 18:22 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 2026-10-07
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-93571
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-93571 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-93571"}
- Public exploit evidencePublic exploit evidence changed from No public exploit to Public exploit reference.CVE.org ↗
- Before
- No public exploit
- After
- Public exploit reference
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
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.