CVE-2026-23956
seroval affected by Denial of Service via RegExp serialization
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
seroval affected by Denial of Service via RegExp serialization
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.
- Record
CVE-2026-23956- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
EUVDEUVD-2026-3669
7.5
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.
- Record
EUVD-2026-3669- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hx9m-jf43-8ffr
7.5
seroval affected by Denial of Service via RegExp serialization
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).
Mitigation:
Seroval introduces disabledFeatures (a bitmask) in serialization/deserialization methods, with Feature.RegExp as a dedicated flag. Users are recommended to configure disabledFeatures to disable RegExp serialization entirely.
- Record
GHSA-hx9m-jf43-8ffr- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2026-23956- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
OSV
7.5
seroval affected by Denial of Service via RegExp serialization
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.
- Record
CVE-2026-23956- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
OSVGHSA-hx9m-jf43-8ffr
7.5
seroval affected by Denial of Service via RegExp serialization
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).
Mitigation:
Seroval introduces disabledFeatures (a bitmask) in serialization/deserialization methods, with Feature.RegExp as a dedicated flag. Users are recommended to configure disabledFeatures to disable RegExp serialization entirely.
- Record
GHSA-hx9m-jf43-8ffr- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1333
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-23956 is a high vulnerability (CVSS 7.5) in Lxsmnsyc Seroval, published January 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.53%, the 45th percentile. Fixed in seroval 1.4.1.
References
github.com/lxsmnsyc/seroval/security/advisories/GHSA-hx9m-jf43-8ffr
github.com/lxsmnsyc/seroval/commit/ce9408ebc87312fcad345a73c172212f2a798060
github.com/lxsmnsyc/seroval/blob/v0.2.0/packages/seroval/src/index.ts
nvd.nist.gov/vuln/detail/CVE-2026-23956
github.com/advisories/GHSA-hx9m-jf43-8ffr
github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23956.json
github.com/lxsmnsyc/seroval