VulnerabilityPublished 19 Jan 2026Updated 20 Jan 2026

CVE-2026-0943: JV HarfBuzz::Shaper · Dependency on Vulnerable Third-Party Component

Affects JV HarfBuzz::ShaperSource CVE Database V5

Mentioned vulnerabilities

CVE-2026-22693

Not known to be exploited · CVSS 7.5 High : upgrade to 0.032 soon.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.032

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade HarfBuzz::Shaper and HarfBuzz-Shaper to 0.032.

Affected software

Product	Affected	Fixed in
JVHarfBuzz::Shaper	Affected <0.032	Fixed in 0.032
GitHubHarfBuzz-Shaper`pkg:github/HarfBuzz-Shaper`Other threats	Affected <0.032	Fixed in 0.032

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade HarfBuzz::Shaper to version 0.032 or later, which includes an updated HarfBuzz library that addresses the null pointer dereference vulnerability.
Audit all software dependencies to identify bundled or linked versions of HarfBuzz 8.4.0 or earlier and update them accordingly.
Implement runtime protections such as application-level monitoring and crash detection to quickly identify and respond to denial of service conditions.
Employ network-level protections like rate limiting and anomaly detection to mitigate potential exploitation attempts.
For organizations unable to immediately upgrade, consider isolating affected services or applying temporary workarounds such as input validation or disabling vulnerable features if feasible.
Maintain an inventory of all Perl modules and third-party libraries to improve supply chain visibility and facilitate rapid response to similar vulnerabilities. 7.

Description

CVE-2026-0943 is a high-severity vulnerability in HarfBuzz::Shaper versions prior to 0.032 for Perl, caused by a null pointer dereference in a bundled HarfBuzz library (version 8.4.0 or earlier). This flaw leads to a denial of service (DoS) condition without requiring authentication or user interaction. The vulnerability stems from a dependency on a vulnerable third-party component, specifically HarfBuzz affected by CVE-2026-22693. Although no known exploits are currently in the wild, the vulnerability's ease of remote exploitation and impact on availability make it a significant risk. European organizations using affected versions in their software stacks, especially those relying on Perl bindings for text shaping or rendering, should prioritize patching or mitigating this issue. Countries with strong software development sectors and extensive use of open-source libraries are more likely to be impacted. Immediate mitigation involves updating to HarfBuzz::Shaper version 0.

Impact

The primary impact of CVE-2026-0943 is denial of service, which can disrupt applications relying on HarfBuzz::Shaper for text rendering. For European organizations, this could affect web services, document processing systems, and any software that integrates Perl bindings for HarfBuzz, potentially causing service outages or degraded user experience. Industries such as publishing, software development, and any sector relying on complex text rendering (e.g., multilingual support) are at risk. The vulnerability does not compromise confidentiality or integrity but can cause availability issues, leading to operational disruptions and potential reputational damage. Since exploitation requires no authentication and can be triggered remotely, attackers could leverage this vulnerability to disrupt critical services. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as exploit code could emerge. European organizations with extensive use of open-source software and Perl modules should be vigilant, as the dependency on vulnerable third-party components is a common supply chain risk.

Summary

CVE-2026-0943 identifies a vulnerability in the JV project's HarfBuzz::Shaper Perl module versions before 0.032. The root cause is a null pointer dereference within the bundled HarfBuzz library (version 8.4.0 or earlier), which is included as hb_src.tar.gz in the source tarball. This underlying HarfBuzz vulnerability is tracked as CVE-2026-22693. The null pointer dereference can be triggered remotely without any authentication or user interaction, resulting in a denial of service by crashing the application or service using the affected library. HarfBuzz is a widely used text shaping engine critical for rendering complex scripts and fonts in many software applications, including web browsers, document processors, and UI frameworks. The dependency on a vulnerable third-party component (CWE-1395) highlights the risk of inherited vulnerabilities through bundled libraries. The CVSS v3.1 score of 7.5 reflects the high impact on availability with network attack vector, low attack complexity, and no privileges or user interaction required. No patches or exploit code are currently publicly available, but the vulnerability is published and should be addressed promptly. Organizations using HarfBuzz::Shaper in Perl environments should verify their versions and update to 0.032 or later, which includes an updated HarfBuzz library free from this flaw.

CWE-1395Dependency on Vulnerable Third-Party Component (opens in a new tab)
Class weaknessOWASP Top 10 A03:2025: Software Supply Chain Failures (opens in a new tab)
The product has a dependency on a third-party component that contains one or more known vulnerabilities.
Requirements · Policy
In some industries such as healthcare or technologies such as the cloud, it might be unclear about who is responsible for applying patches for third-party vulnerabilities: the vendor, the operator/customer, or a separate service.
Requirements
Require a Bill of Materials for all components and sub-components of the product. For software, require a Software Bill of Materials (SBOM).
Architecture and Design · Implementation · Integration · Manufacturing
Maintain a Bill of Materials for all components and sub-components of the product. For software, maintain a Software Bill of Materials (SBOM). According to, "An SBOM is a formal, machine-readable inventory of software components and dependencies, information about those components, and their hierarchical…
OWASP Cheat Sheets
OWASP Cheat Sheet Series: Dependency Graph SBOM (opens in a new tab)
OWASP Cheat Sheet Series: Vulnerable Dependency Management (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Jan 2026, 20:06 UTC

WeaknessesCWE-1395

Technical details

References

Community reviews

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