Security readout for executives and security teams
Plain-English summary
Cal.com through version 4.7.15 can let an authorized event creator place malicious web content inside booking-question labels. When someone opens the resulting booking page, attacker-controlled JavaScript can run in that visitor’s browser, potentially exposing sensitive information or enabling actions in the visitor’s session.
Executive priority
Treat internet-facing affected deployments as an urgent patching priority, especially where customers, partners, or broad internal groups can create event types. Upgrade promptly and review existing content. The severity is critical, but the available sources do not establish active exploitation.
Technical view
The single booking view renders attacker-controlled booking-question labels using React dangerouslySetInnerHTML without adequate sanitization or escaping. Exploitation requires permission to create an event type and victim interaction with its booking URL. The vulnerability is classified as CWE-80, scores 9.3 under CVSS 4.0, and is fixed in version 4.7.16.
Likely exposure
Self-hosted Cal.com/cal.diy deployments through 4.7.15 are likely exposed when potentially untrusted or compromised accounts can create event types. Actual risk depends on account permissions, existing malicious booking questions, and whether users visit crafted booking links. The bundle’s structured affected-version entry is inconsistent with its advisory narrative, so confirm scope against the vendor advisory.
Exploitation context
The attack is remotely reachable but requires low privileges and victim interaction. A malicious event creator embeds active content in a booking-question label, then persuades a victim to open the booking page. The bundle reports no CISA KEV listing and provides no evidence of active exploitation in the wild.
Researcher notes
The source bundle’s narrative, vendor advisory reference, and patch identify versions through 4.7.15 as affected and 4.7.16 as fixed. However, its structured affected record lists version “0” with default status “unaffected.” Validate exact product and version mapping before reporting fleet-wide exposure. No exploit-in-the-wild evidence is supplied.
Mitigation direction
- Upgrade Cal.com/cal.diy to version 4.7.16 or later.
- Until upgraded, restrict event-type creation and modification to trusted administrators.
- Review booking-question labels and remove unexpected HTML or script content.
- Consult the vendor advisory and patch commit for deployment-specific guidance.
Validation and detection
- Inventory deployed Cal.com/cal.diy versions and flag version 4.7.15 or earlier.
- Confirm the deployed build includes the changes from patch commit 00689fda0a30b8f933c096f02c1fe092a4206def.
- Review which accounts can create or modify event types and booking questions.
- Inspect existing booking-question labels for unexpected active web content.
- Verify booking-question labels no longer execute or render attacker-controlled HTML after upgrading.
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-80: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2024-58355 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
- Critical
- CVSS
- 9.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L
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:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L——VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L2.36VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L
Base CVSS 3.1 score
8.9HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
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
- GitHub Security Advisory (GHSA-vgj7-76cw-h6f8)CVE reference, VulnCheck · vendor-advisory
- Patch CommitCVE reference, VulnCheck · patch
- VulnCheck Advisory: Cal.com through 4.7.15 Cross-Site Scripting via booking questionsCVE 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.
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.