How severe is CVE-2026-23956?

CVE-2026-23956 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-23956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-23956?

CVE-2026-23956 affects Lxsmnsyc Seroval. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-23956?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-23956 have an EU (EUVD) identifier?

Yes. CVE-2026-23956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3669.

When was CVE-2026-23956 published?

CVE-2026-23956 was published on 2026-01-22 and last updated on 2026-06-17.

CVE-2026-23956

CVE-2026-23956 is a high-severity vulnerability in Lxsmnsyc Seroval with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3669
Weakness: CWE-1333
Affected product: Lxsmnsyc Seroval
Published: 2026-01-22
Last modified: 2026-06-17

Description

seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 0.2.0 through 1.4.0, overriding RegExp serialization with extremely large patterns can exhaust JavaScript runtime memory during deserialization. Additionally, overriding RegExp serialization with patterns that trigger catastrophic backtracking can lead to ReDoS (Regular Expression Denial of Service). This issue has been fixed in version 1.4.1.

Frequently asked questions

What is CVE-2026-23956?: seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In versions 0.2.0 through 1.4.0, overriding RegExp serialization with extremely large patterns can exhaust JavaScript runtime memory during deserialization. Additionally, overriding RegExp serialization with patterns that trigger catastrophic backtracking can lead to ReDoS (Regular Expression Denial of Service). This issue has been fixed in version 1.4.1.
How severe is CVE-2026-23956?: CVE-2026-23956 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-23956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23956?: CVE-2026-23956 affects Lxsmnsyc Seroval. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23956?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23956 have an EU (EUVD) identifier?: Yes. CVE-2026-23956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3669.
When was CVE-2026-23956 published?: CVE-2026-23956 was published on 2026-01-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:lxsmnsyc:seroval:*:*:*:*:*:node.js:*:*

More vulnerabilities in Lxsmnsyc Seroval

CVE-2026-24006 — High (CVSS 7.5): Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In…
CVE-2026-23957 — High (CVSS 7.5): seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In…
CVE-2026-23737 — High (CVSS 7.5): seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In…
CVE-2026-23736 — High (CVSS 7.3): seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. In…

All CVEs affecting Lxsmnsyc Seroval →

Other CWE-1333 vulnerabilities

CVE-2026-35458 — Critical (CVSS 9.8): Gotenberg is an API for converting document formats. In 8.29.1 and earlier, Gotenberg uses dlclark/regexp2 to compile…
CVE-2023-29486 — Critical (CVSS 9.8): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before 3.7.0 on Windows, allows attackers to bypass…
CVE-2026-25547 — Critical (CVSS 9.2): @isaacs/brace-expansion is a hybrid CJS/ESM TypeScript fork of brace-expansion. Prior to version 5.0.1,…
CVE-2023-29487 — Critical (CVSS 9.1): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS,…
CVE-2026-47138 — High (CVSS 8.7): Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to…
CVE-2025-6998 — High (CVSS 8.7): ReDoS in strip_whitespaces() function in cps/string_helper.py in Calibre Web and Autocaliweb allows unauthenticated…

Browse all CWE-1333 vulnerabilities →