Security readout for executives and security teams
Plain-English summary
CVE-2026-23956 affects the JavaScript package seroval. If an application deserializes attacker-influenced serialized RegExp data, crafted patterns can consume excessive memory or CPU, causing denial of service. The issue affects versions 0.2.0 through 1.4.0 and is fixed in 1.4.1.
Executive priority
Prioritize remediation for internet-facing or multi-tenant services that deserialize untrusted seroval data. The business risk is outage or degraded availability. If seroval is only used with trusted internal data, urgency is lower but upgrade remains recommended.
Technical view
seroval supports serialization of complex JavaScript values. In affected versions, overridden RegExp serialization can deserialize extremely large patterns that exhaust runtime memory, or patterns that cause catastrophic backtracking, resulting in ReDoS. CVSS 3.1 is 7.5, network exploitable, low complexity, no privileges or user interaction, availability impact only.
Likely exposure
Exposure is most likely in Node.js or JavaScript applications using seroval versions >=0.2.0 and <1.4.1 where serialized input can be influenced by untrusted users, clients, tenants, or external services.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not marked KEV. Practical risk depends on whether applications deserialize attacker-controlled seroval data containing RegExp values. Impact is service disruption, not documented data theft or code execution.
Researcher notes
The advisory identifies CWE-1333 and two denial-of-service modes: memory exhaustion from very large RegExp patterns and ReDoS from catastrophic backtracking. The public bundle names the fixed version and commit but does not provide evidence of exploitation in the wild.
Mitigation direction
- Upgrade seroval to version 1.4.1 or later.
- Identify applications and transitive dependencies using affected seroval versions.
- Restrict or reject untrusted serialized data until upgraded.
- Review vendor advisory and commit for implementation-specific guidance.
- Monitor application availability metrics after remediation.
Validation and detection
- Check package manifests and lockfiles for seroval versions >=0.2.0 and <1.4.1.
- Confirm deployed artifacts use seroval 1.4.1 or later.
- Map code paths that deserialize externally supplied seroval payloads.
- Verify dependency scanners flag CVE-2026-23956 where applicable.
- Review logs for unexplained memory exhaustion or CPU saturation.
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-1333: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-23956 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
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:N/I:N/A:H3.93.6GitHub_MVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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/lxsmnsyc/seroval/security/advisories/GHSA-hx9m-jf43-8ffrCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/lxsmnsyc/seroval/blob/v0.2.0/packages/seroval/src/index.ts#L90CVE reference, GitHub_M · 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.
Inefficient Regular Expression Complexity
Inefficient Regular Expression Complexity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.