Security readout for executives and security teams
Plain-English summary
Summarize browser extension before 0.15.1 allowed a malicious webpage visited by a user to misuse the extension’s message bridge. The page could access or alter automation artifacts for that tab, including reading, creating, overwriting, or deleting them. This is not server compromise, but it can expose sensitive automation data.
Executive priority
Treat this as a moderate browser-extension exposure. It needs timely remediation for affected users, especially those using automation artifacts with sensitive business content, but current sources do not support emergency active-exploitation handling.
Technical view
The content script window.postMessage bridge lacked proper authorization checks. Malicious pages could spoof sender identifiers and simulate runtime messages, triggering unauthorized artifact operations scoped to the affected tab. The CVSS 3.1 score is 6.1 with network attack vector, low complexity, no privileges required, and user interaction required.
Likely exposure
Exposure is limited to users running the steipete Summarize browser extension before 0.15.1 who visit attacker-controlled or compromised pages. Impact is scoped to automation artifacts associated with the affected tab, not broadly documented as full browser or host compromise.
Exploitation context
The source bundle does not report active exploitation, and KEV status is false. Exploitation requires user interaction because a user must browse to a malicious page where the page can abuse the extension bridge.
Researcher notes
Focus review on the content-script postMessage trust boundary, sender validation, and artifact operation authorization. The documented impact is unauthorized list, read, create, overwrite, and delete operations for tab-scoped automation artifacts. Evidence is strongest for versions before 0.15.1; no exploit status beyond the source bundle is provided.
Mitigation direction
- Upgrade Summarize to 0.15.1 or later; prefer the latest available release.
- Prioritize version 0.15.2 where the referenced release is available.
- Remove or disable vulnerable extension versions until upgraded.
- Review vendor release notes, PR 222, and patch commit for implementation details.
- Limit use of the extension on untrusted websites where possible.
Validation and detection
- Inventory browsers for installed Summarize extension versions below 0.15.1.
- Confirm managed browser policies deploy only patched Summarize versions.
- Check whether affected users handled sensitive automation artifacts in browser tabs.
- Review extension update telemetry or endpoint inventory for upgrade completion.
- Monitor vendor and CVE records for any changed exploitation or remediation guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-45243 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.3MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/steipete/summarize/releases/tag/v0.15.2CVE reference, VulnCheck · release-notes
- https://github.com/steipete/summarize/pull/222CVE reference, VulnCheck · issue-tracking
- https://github.com/steipete/summarize/commit/357544063af535bd574752622f9eb94be33ee5fdCVE reference, VulnCheck · patch
- https://www.vulncheck.com/advisories/summarize-browser-extension-missing-authorization-via-content-scriptCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.