# CVE-2026-22693: Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS

> A null pointer dereference in HarfBuzz allows attackers to cause a denial of service via memory allocation failures.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Jan 2026
- **Updated:** 12 Jan 2026
- **Also known as:** AZL-73970, DEBIAN-CVE-2026-22693, ECHO-7ecb-7a01-33a3, GHSA-xvjr-f2r9-c7ww, JLSEC-2026-777, MGASA-2026-0015, OESA-2026-1149, OESA-2026-1150, OESA-2026-1203, OESA-2026-1204, RHSA-2026:7701, ROOT-OS-DEBIAN-11-CVE-2026-22693, ROOT-OS-DEBIAN-12-CVE-2026-22693, SUSE-SU-2026:0287-1, SUSE-SU-2026:20762-1, SUSE-SU-2026:20922-1, UBUNTU-CVE-2026-22693, openSUSE-SU-2026:10065-1, openSUSE-SU-2026:20409-1

## What is CVE-2026-22693?

CVE-2026-22693 is a medium-severity vulnerability in harfbuzz, published on 10 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-22693?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `harfbuzz` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-cairo` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-devel` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-gpu` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-icu` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-raster` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz-vector` | Red Hat:hummingbird:1 | All versions | 0:14.1.0-2.hum1 |
| `harfbuzz` | SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 8.3.0-150600.3.3.1 |
| `harfbuzz` | SUSE:Linux Enterprise Server 16.0 | All versions | 11.4.5-160000.1.1 |
| `harfbuzz` | SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 11.4.5-160000.1.1 |
| `harfbuzz` | SUSE:Linux Micro 6.2 | All versions | 11.4.5-160000.1.1 |
| `harfbuzz` | openSUSE:Leap 15.6 | All versions | 8.3.0-150600.3.3.1 |
| `harfbuzz` | openSUSE:Leap 16.0 | All versions | 11.4.5-160000.1.1 |
| `harfbuzz` | openSUSE:Tumbleweed | All versions | 12.3.0-2.1 |

Products: Harfbuzz Project Harfbuzz.

## How do I fix CVE-2026-22693?

Upgrade to a fixed version.

## Is CVE-2026-22693 being exploited?

There is no known exploitation of CVE-2026-22693 in the wild and no public exploit code.

## Other vulnerabilities in harfbuzz

- [CVE-2024-56732](https://insights.sbomify.com/CVE-2024-56732/): HarfBuzz heap-buffer-overflow on hb_cairo_glyphs_from_buffer (critical 9.3)
- [CVE-2015-8947](https://insights.sbomify.com/CVE-2015-8947/): Memory corruption in n/a (high 7.6)
- [CVE-2015-9274](https://insights.sbomify.com/CVE-2015-9274/): Denial of service in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22693 and fix it if it is affected.

What it is: CVE-2026-22693 is a medium-severity vulnerability in harfbuzz, published on 10 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-22693 in the wild and no public exploit code.

Affected product: harfbuzz. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-22693/ (Markdown: https://insights.sbomify.com/CVE-2026-22693/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22693
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22693
- OSV: https://osv.dev/vulnerability/CVE-2026-22693

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22693/
Summaries are generated and may contain mistakes; the official description above is the record.