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🛡️ CVE-2023-50262 — dompdf

🟡 CVSS 5.3 — Medium ⚠️ Exploit Public CWE-20 NVD
5.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Denial of service caused by infinite recursion when parsing SVG images

Summary

When parsing SVG images Dompdf performs an initial validation to ensure that paths within the SVG are allowed. One of the validations is that the [SVG document does not reference itself](https://github.com/dompdf/dompdf/blob/v2.0.3/src/Image/Cache.php#L136-L153). However, a recursive chained using two or more SVG documents is not correctly validated. Depending on the system configuration and attack pattern this could exhaust the memory available to the executing process and/or to the server itself.

Details

php-svg-lib, when run in isolation, does not support SVG references for image elements. An SVG document can, however, be referenced and Dompdf will run that reference through the same validation. Dompdf currently includes validation to prevent self-referential image references, but a chained reference is not checked. A malicious actor may thus trigger infinite recursion in the validation process by chaining references between two or more SVG images.

PoC

This following sources can be used to bypass validation provided by Dompdf:

recurse.html

```

<img src="one.svg">

```

one.svg

```

<svg width="200" height="200" xmlns="http://www.w3.org/2000/svg">

<image href="two.svg" />

</svg>

```

two.svg

```

<svg width="200" height="200" xmlns="http://www.w3.org/2000/svg">

<image href="one.svg" />

</svg>

```

Impact

When Dompdf parses the above payload, it will crash due after exceeding the allowed execution time or memory usage. An attacker sending multiple request to a system can potentially cause resource exhaustion to the point that the system is unable to handle incoming request.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability low.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: Low — limited, and the attacker does not choose what is affected.

Weakness class

CVE-2023-50262 is classified as CWE-20: Improper Input Validation. The application accepts input without checking that it has the expected form, so malformed values reach code that assumes they are well formed.

Affected software

CVE-2023-50262 is recorded against 2 packages.

  • dompdf (fixed in 2.0.3)
  • dompdf/dompdf (fixed in 2.0.4)

Timeline and source

Published on 13 December 2023 and last revised on 17 June 2026. A public exploit is known to exist, which raises the urgency of patching considerably. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
github.com
github.com
github.com

Other advisories for this package

dompdf has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-20: Improper Input Validation) in other software:

CVE-2023-50262 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity MEDIUM
CVSS Score 5.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE CWE-20
Public Exploit ⚠️ Yes
Source NVD
Published 2023-12-13
Updated 2026-08-20
Modified 2026-06-17

Affected Packages

Software From version Fixed in
dompdf — 2.0.3
dompdf/dompdf — 2.0.4

Exploit Protection

Are you running dompdf?

CVE-2023-50262 carries CVSS 5.3 Medium rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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