CVE-2020-25464: Heap buffer overflow at moddable/xs/sources/xsDebug.c in Moddable SDK before before 20200903

Q: How do I fix CVE-2020-25464?

moddable: upgrade to os200903. Exact commands for each OS are on this page.

Q: Is CVE-2020-25464 being exploited?

CVE-2020-25464 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-25464 affect?

CVE-2020-25464 affects moddable. Severity is high (CVSS 7.5). Heap buffer overflow at moddable/xs/sources/xsDebug.c in Moddable SDK before before 20200903. The top stack frame is only partially initialized because the stack overflowed while creating the frame. This leads to a crash in the code sending

Q: How urgent is CVE-2020-25464?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2020-25464 is a high-severity flaw (CVSS 7.5) affecting moddable. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Heap buffer overflow at moddable/xs/sources/xsDebug.c in Moddable SDK before before 20200903. The top stack frame is only partially initialized because the stack overflowed while creating the frame. This leads to a crash in the code sending the stack frame to the debugger.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-787
Published	2020-12-04
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: moddable

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-12-04 17:15 UTCPublished CVE record published
2026-06-17 03:06 UTCUpdated Record last modified

moddable moddable UPGRADE

Affected: < os200903

Fixed in: os200903

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy moddable || rpm -q moddable || moddable --version

2. UPGRADE to os200903 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade moddable

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade moddable

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-25464?

moddable: upgrade to os200903. Exact commands for each OS are on this page.

Is CVE-2020-25464 being exploited?

CVE-2020-25464 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-25464 affect?

CVE-2020-25464 affects moddable. Severity is high (CVSS 7.5). Heap buffer overflow at moddable/xs/sources/xsDebug.c in Moddable SDK before before 20200903. The top stack frame is only partially initialized because the stack overflowed while creating the frame. This leads to a crash in the code sending

How urgent is CVE-2020-25464?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

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References

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