Panda3D: Out-of-bounds Write
CVE-2026-22189 is a critical-severity out-of-bounds write vulnerability in Panda3D, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Panda3D versions: 1.10.16 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.52% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Panda3D you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (vulncheck.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
The egg-mkfont utility in Panda3D versions up to and including 1.10.16 contains a stack-based buffer overflow vulnerability due to use of an unbounded sprintf() call with attacker-controlled input. When constructing glyph filenames, egg-mkfont formats a user-supplied glyph pattern (-gp) into a fixed-size stack buffer without length validation. Supplying an excessively long glyph pattern string can overflow the stack buffer, resulting in memory corruption and a deterministic crash. Depending on build configuration and execution environment, the overflow may also be exploitable for arbitrary code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vulncheck.com/advisories/panda3d-egg-mkfont-stack-buffer-overflowThird Party Advisory
Technical write-ups (may include proof of concept)
- seclists.org/fulldisclosure/2026/Jan/10Exploit, Mailing List, Third Party Advisory
Other references
- github.com/panda3d/panda3dProduct
- panda3d.org/Product
Other vulnerabilities in Panda3D
- 7.5 High severity
Recent Out-of-bounds Write vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
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