Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.11% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-106243High confidence
Incomplete cleanup in Proxy Auth in Google Chrome prior to 155.0.8059.39 allowed an adjacent attacker to obtain sensitive information via crafted network traffic
Google · Chrome
5.3MediumCVSS 3.1
Scheduled
Fix not verifiedMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Google Chrome 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.
Distribution package intelligence
4 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
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 release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | chromium | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 9 Oct 2026 |
| Debian bookwormbookworm · source | chromium | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 9 Oct 2026 |
| Debian forkyforky · source | chromium | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 9 Oct 2026 |
| Debian sidsid · source | chromium | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 9 Oct 2026 |
Direct vendor intelligence
1 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-2026-106243 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitychromium-browser: Incomplete cleanup in Proxy Auth
The vendor explicitly states that these products are not affected by this CVE.
- All currently supported Red Hat products
- Summary
- An incomplete cleanup flaw was found in the Proxy Auth component of the Chromium browser. Upstream bug(s): https://issues.chromium.org/issues/533426590
- Remediation
- No remediation text is recorded.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Fix not verified01
What, why and how
Incomplete cleanup in Proxy Auth in Google Chrome prior to 155.0.8059.39 allowed an adjacent attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: High)
What
Incomplete cleanup in Proxy Auth in Google Chrome prior to 155.0.8059.39 allowed an adjacent attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: High)
Why
The product does not properly clean up and remove temporary or supporting resources after they have been used.
How
An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.
What
Incomplete cleanup in Proxy Auth in Google Chrome prior to 155.0.8059.39 allowed an adjacent attacker to obtain sensitive information via crafted network traffic. (Chromium security severity: High)
Why
The product does not properly clean up and remove temporary or supporting resources after they have been used.
How
An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.
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
- an adjacent network → Incomplete Cleanup → obtain information outside the intended access boundary
- Attack surface
- Adjacent
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-459 ↗
CWE-459: Incomplete Cleanup. The product does not properly clean up and remove temporary or supporting resources after they have been used.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCommon Vulnerability Scoring System 3.1: 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.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.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 not verified
- Affected
- Chrome: 155.0.8059.39 < 155.0.8059.39
- 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, 20:40 UTC · CWE-459 · Incomplete Cleanup
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
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-2026-93809
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
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-93809 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-93809"}
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html.chrome-cve-admin@google.com ↗
- Before
- no authoritative guidance recorded
- After
- vendor advisory: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html
- SeveritySeverity changed from Unknown to Medium.CISA ADP ↗
- Before
- Unknown
- After
- Medium
- CVSS scoreCVSS score changed from not recorded to 5.3 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).CISA ADP ↗
- Before
- not recorded
- After
- 5.3 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)
- Vendor guidanceAuthoritative vendor guidance changed: removed patch: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html; removed remediation: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html.CNA ↗
- Before
- patch: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html · remediation: chromereleases.googleblog.com/stable-channel-update-for-desktop_086471744.html
- After
- no authoritative guidance recorded
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- Google Chrome desktop releases before the fixed versions in the linked Stable Channel advisory. · Fixed: Google has published a fixed Chrome Stable desktop release in the linked advisory.
- After
- Chrome: 155.0.8059.39 < 155.0.8059.39 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Remediation statusRemediation status changed from Patch available to Awaiting fix.CNA ↗
- Before
- Patch available
- After
- Awaiting fix
- SeveritySeverity changed from High to Unknown.CVE.org ↗
- Before
- High
- After
- Unknown
- Catalogue recordCVE added to the BlackTree catalogue.Authoritative vendor advisory ↗
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.