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TI-2025-38738 Aliases CVE-2025-62496GHSA-p8pr-fr36-rgmq

Integer overflow in js_bigint_from_string in QuickJS

Priority HIGH 66CWE-190Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
Low
User interaction
Passive
Attack complexity
High
Attack requirements
Present
Impact type
Code execution
Confidentiality · integrity · availability
High · High · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-190 and the CVSS impact.

Summary

A vulnerability exists in the QuickJS engine's BigInt string parsing logic (js_bigint_from_string) when attempting to create a BigInt from a string with an excessively large number of digits. The function calculates the necessary number of bits (n_bits) required to store the BigInt using the formula: $$\text{n\_bits} = (\text{n\_digits} \times 27 + 7) / 8 \quad (\text{for radix 10})$$ * For large input strings (e.g., $79,536,432$ digits or more for base 10), the intermediate calculation $(\text{n\_digits} \times 27 + 7)$ exceeds the maximum value of a standard signed 32-bit integer, resulting in an Integer Overflow. * The resulting n_bits value becomes unexpectedly small or even negative due to this wrap-around. * This flawed n_bits is then used to compute n_limbs, the number of memory "limbs" needed for the BigInt object. Since n_bits is too small, the calculated n_limbs is also significantly underestimated. * The function proceeds to allocate a JSBigInt object using this underestimated n_limbs. * When the function later attempts to write the actual BigInt data into the allocated object, the small buffer size is quickly exceeded, leading to a Heap Out-of-Bounds Write as data is written past the end of the allocated r->tab array.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00491 42nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed QuickJS (QuickJS): 2025-09-13

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
QuickJSQuickJS2025-04-26 to before 2025-09-132025-09-13Patch availableCNA
  • QuickJS VendorQuickJS Affected 2025-04-26 to before 2025-09-13 Fixed in 2025-09-13 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:quickjs_project:quickjs:*:*:*:*:*:*:*:*before 2025-09-13VulnerableQuickJS
  • cpe:2.3:a:quickjs_project:quickjs:*:*:*:*:*:*:*:* Versions before 2025-09-13 Vulnerable ·QuickJS

Remediation

  • Fix · CNA QuickJS (QuickJS) Fixed in 2025-09-13

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    QuickJS 2025-09-13

    7 records Highest priority Priority HIGH 4 HIGH, 3 MEDIUM

    Other records, highest priority first

    • TI-2025-38733 Use-after-free in js_std_promise_rejection_check in QuickJSPriority HIGH 73
    • TI-2025-38737 Type confusion in string addition in QuickJSPriority HIGH 66
    • TI-2025-38736 Type confusion in string addition in QuickJSPriority HIGH 66
    Show all 7 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-62496
  2. 2026-10-03 Alias added: GHSA-p8pr-fr36-rgmq

References

Exploit 1

Other 1

  • TI-2025-38733 Use-after-free in js_std_promise_rejection_check in QuickJS CVSS 4.0HIGH 8.8
  • TI-2025-42911 A crafted JavaScript input executed with the QuickJS release 2025-09-13, fixed in commit… CVSS 3.1HIGH 7.5
  • TI-2025-29366 quickjs-ng through 0.9.0 has an incorrect size calculation in JS_ReadBigInt for a BigInt… CVSS 3.1HIGH 8.4
  • TI-2025-38737 Type confusion in string addition in QuickJS CVSS 4.0HIGH 7.1
  • TI-2025-38736 Type confusion in string addition in QuickJS CVSS 4.0HIGH 7.1
  • TI-2023-15270 QuickJS commit 2788d71 was discovered to contain a stack-overflow via the component js_proxy_isArray at quickjs.c. CVSS 3.1HIGH 7.5
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences