Security readout for executives and security teams
Plain-English summary
CVE-2026-23736 affects seroval, a JavaScript serialization library. Versions 1.4.0 and below can allow prototype pollution when using JSON deserialization with malicious object keys. The issue is fixed in version 1.4.1. Business urgency is highest for applications that deserialize untrusted or user-controlled JSON through seroval.
Executive priority
Treat as a high-priority dependency update for JavaScript applications that process external JSON. The fix is available, and validation should focus on whether affected seroval versions are present in production and whether JSON deserialization is reachable from untrusted input.
Technical view
The vulnerability is improper input validation in seroval JSON deserialization, classified as CWE-1321 prototype pollution. The CVSS 3.1 score is 7.3, with network attack vector, low complexity, no privileges, and no user interaction. The advisory states only JSON deserialization functionality is affected. A fixing commit and version 1.4.1 are referenced.
Likely exposure
Exposure is likely where applications or dependencies use seroval versions below 1.4.1 and invoke its JSON deserialization functionality on untrusted input. Projects using seroval only for other functionality may have lower exposure, based on the advisory’s scope statement.
Exploitation context
The provided sources do not report active exploitation, and this CVE is not marked as CISA KEV in the bundle. The risk comes from attacker-controlled keys causing prototype pollution during deserialization, which can affect confidentiality, integrity, and availability at low impact levels per CVSS.
Researcher notes
Evidence is limited to the CVE record, GitHub advisory, and fixing commit. The advisory narrows impact to JSON deserialization. No public source in the bundle indicates exploitation in the wild. Further triage should examine dependency reachability and whether polluted prototypes can influence application security decisions.
Mitigation direction
- Upgrade seroval to version 1.4.1 or later.
- Prioritize services that deserialize untrusted JSON with seroval.
- If upgrade timing is constrained, review vendor advisory for supported guidance.
- Avoid passing untrusted JSON into affected deserialization paths until remediated.
Validation and detection
- Inventory direct and transitive seroval dependencies.
- Confirm deployed versions are 1.4.1 or later.
- Identify code paths using seroval JSON deserialization.
- Check whether those paths accept user-controlled or external JSON.
- Review the referenced fixing commit and advisory for implementation details.
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
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ATT&CK lookup starting points
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CWE-1321: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-23736 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A: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.
CVSS vector scores
1 official scoreWe 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:N/S:U/C:L/I:L/A:L3.93.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-hj76-42vx-jwp4CVE reference · x_refsource_CONFIRM
- https://github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060CVE reference · x_refsource_MISC
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.
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.