CVE-2026-23737: seroval Affected by Remote Code Execution via JSON Deserialization
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.58% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: lxsmnsyc seroval 1.4.0.
Low priority for now. Upgrade to lxsmnsyc seroval 1.4.0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 1.4.0 and below, improper input handling in the JSON deserialization component can lead to arbitrary JavaScript code execution. Exploitation is possible via overriding constant value and error deserialization, allowing indirect access to unsafe JS evaluation. At minimum, attackers need the ability to perform 4 separate requests on the same function, and partial knowledge of how the serialized data is used during later runtime processing. This vulnerability affects the fromJSON and fromCrossJSON functions in a client-to-server transmission scenario. This issue has been fixed in version 1.4.0.
- Published
- Jan 21, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.5% · 47th percentile
- CWE
- CWE-502
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 7.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| lxsmnsyc | seroval | cpe:2.3:a:lxsmnsyc:seroval |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- lxsmnsyc serovalbefore 1.4.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
lxsmnsyc seroval
- < 1.4.1affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | seroval | before 1.4.1 | 1.4.1 |
| openSUSE:Tumbleweed | opencode | before 1.18.26-1.1 | 1.18.26-1.1 |
Same product
lxsmnsyc: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-104846Seroval: `fromJSON()` Promise thenable assimilation invokes plugin-produced callables (bypass of CVE-2026-59940)39Monitor
- CVE-2026-59940Seroval: `seroval.fromJSON()` Promise resolver type confusion invokes attacker-controlled methods during deserialization39Monitor
- CVE-2026-23736seroval Affected by Prototype Pollution via JSON Deserialization39Monitor
Published before and after this one in the same product
- Later →CVE-2026-23956Jan 21, 2026 · seroval affected by Denial of Service via RegExp serialization30Monitor
- Later →CVE-2026-23957Jan 21, 2026 · seroval is vulnerable to Denial of Service via array serialization30Monitor
- Later →CVE-2026-24006Jan 21, 2026 · Seroval affected by Denial of Service via Deeply Nested Objects30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| lxsmnsyc seroval | 1.4.0 · description | Vendor (CNA) |
| npm:seroval | 1.4.1 | Package registry (OSV) |
| opensuse:opencode | 1.18.26-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-59940209 days apartSeroval: `seroval.fromJSON()` Promise resolver type confusion invokes attacker-controlled methods during deserialization39Monitor
- CVE-2026-116580278 days apartSeroval: Deserialization invokes attacker-chosen callables: AsyncIteratorFactoryInstance calls source.on(listener) without type check29Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-502 · Deserialization of Untrusted DataCVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Root cause
Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.
The bug in code
The whole CWE-502 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
payload = sock.recv(65536)
job = pickle.loads(payload)Fixed
payload = sock.recv(65536)
if not hmac.compare_digest(sign(payload), header_sig):
raise PermissionError("invalid signature")
job = JobSchema.validate(json.loads(payload))Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.