CVE-2025-62492
Heap out-of-bounds read in js_typed_array_indexOf in QuickJS
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.9
Heap out-of-bounds read in js_typed_array_indexOf in QuickJS
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
CVE-2025-62492- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2025-34782
5.9
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
EUVD-2025-34782- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7x74-j54q-cmv6
5.9
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS...
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
GHSA-7x74-j54q-cmv6- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
5.9
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
CVE-2025-62492- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
OSV
6.5
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied.
-
The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search.
-
If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d:
$$d_{new} = d + \text{len}$$
-
Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$.
-
The result is then converted to an integer index $k$: $k = \text{len}$.
-
The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array.
This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
CVE-2025-62492- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2025-62492
6.5
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied. * The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search. * If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d: $$d_{new} = d + \text{len}$$ * Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$. * The result is then converted to an integer index $k$: $k = \text{len}$. * The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array. This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
DEBIAN-CVE-2025-62492- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-62492
5.9
A vulnerability stemming from floating-point arithmetic precision errors exists in the QuickJS engine's implementation of TypedArray.prototype.indexOf() when a negative fromIndex argument is supplied. * The fromIndex argument (read as a double variable, $d$) is used to calculate the starting position for the search. * If d is negative, the index is calculated relative to the end of the array by adding the array's length (len) to d: $$d_{new} = d + \text{len}$$ * Due to the inherent limitations of floating-point arithmetic, if the negative value $d$ is extremely small (e.g., $-1 \times 10^{-20}$), the addition $d + \text{len}$ can result in a loss of precision, yielding an outcome that is exactly equal to $\text{len}$. * The result is then converted to an integer index $k$: $k = \text{len}$. * The search function proceeds to read array elements starting from index $k$. Since valid indices are $0$ to $\text{len}-1$, starting the read at index $\text{len}$ is one element past the end of the array. This allows an attacker to cause an Out-of-Bounds Read of one element immediately following the buffer. While the scope of this read is small (one element), it can potentially lead to Information Disclosure of adjacent memory contents, depending on the execution environment.
- Record
UBUNTU-CVE-2025-62492- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
quickjsDebian:13 |
All versions, plus listed versions 2025.04.26-1 |
None known |
quickjsDebian:14 |
All versions, plus listed versions 2025.04.26-1 |
None known |
quickjsUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 2021.03.27-12021.03.27-1ubuntu0.1~esm1 |
None known |
quickjsUbuntu:25.10 |
All versions, plus listed versions 2024.01.13-52025.04.26-1 |
None known |
quickjsUbuntu:26.10 |
All versions, plus listed versions 2025.04.26-1build1 |
None known |
quickjsUbuntu:26.04:LTS |
All versions, plus listed versions 2025.04.26-12025.04.26-1build1 |
None known |
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-2025-62492 is a medium vulnerability (CVSS 5.9) in Quickjs, published October 16, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 34th percentile. No source names a fixed version.