CVE-2023-36109: Buffer Overflow vulnerability in JerryScript version 3.0, allows remote attackers to execute arbitrary code vi

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2023-36109 is a critical-severity flaw (CVSS 9.8) affecting jerryscript. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer Overflow vulnerability in JerryScript version 3.0, allows remote attackers to execute arbitrary code via ecma_stringbuilder_append_raw component at /jerry-core/ecma/base/ecma-helpers-string.c.

Why this priority

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

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-120
Published	2023-09-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: jerryscript

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

Am I affected?

Timeline

2023-09-20 22:15 UTCPublished CVE record published
2026-06-17 06:05 UTCUpdated Record last modified

jerryscript jerryscript DOWNGRADE

Affected: 3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.0 (Debian / Ubuntu)

apt-cache madison jerryscript sudo apt install jerryscript=<VERSION_BEFORE_3.0> sudo apt-mark hold jerryscript

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jerryscript sudo dnf downgrade jerryscript-<VERSION_BEFORE_3.0> sudo dnf versionlock add jerryscript

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2023-36109?

jerryscript: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-36109 being exploited?

CVE-2023-36109 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-2023-36109 affect?

CVE-2023-36109 affects jerryscript. Severity is critical (CVSS 9.8). Buffer Overflow vulnerability in JerryScript version 3.0, allows remote attackers to execute arbitrary code via ecma_stringbuilder_append_raw component at /jerry-core/ecma/base/ecma-helpers-string.c.

How urgent is CVE-2023-36109?

Priority 65/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2024-33260 MEDIUM 5.1 DOWNGRADE Jerryscript commit cefd391 was discovered to contain a segmentation violation via the component parser_parse_c
CVE-2024-33259 MEDIUM 5.5 DOWNGRADE Jerryscript commit cefd391 was discovered to contain a segmentation violation via the component scanner_seek a
CVE-2024-33258 HIGH 7.1 DOWNGRADE Jerryscript commit ff9ff8f was discovered to contain a segmentation violation via the component vm_loop at jer
CVE-2024-33255 MEDIUM 6.2 DOWNGRADE Jerryscript commit cefd391 was discovered to contain an Assertion Failure via ECMA_STRING_IS_REF_EQUALS_TO_ONE
CVE-2024-29489 MEDIUM 5.5 UPGRADE Jerryscript 2.4.0 has SEGV at ./jerry-core/ecma/base/ecma-helpers.c:238:58 in ecma_get_object_type.

References

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