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Vulnerabilities

Vulnerability · GHSA-6fj4-rcr3-r7rr

lopdf has a stack overflow via deeply nested PDF objects

Published Oct 16, 2026 · catalog updated Oct 17, 2026 · lopdf has a stack

Open the advisory

Exploitation likelihood is not on this record for GHSA-6fj4-rcr3-r7rr. A missing EPSS score is not a low risk. Compare lopdf has a stack with the linked advisory before you change production.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (lopdf has a stack).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Awaiting synchronization with FIRST
Remediation
Version ranges on file
Affected products
crates.io lopdf · rust lopdf

(and the other entry points) parses nested PDF arrays and dictionaries with unbounded recursion. A small crafted PDF whose Catalog contains a deeply nested array ( , on the order of 10,000 levels) exhausts the call stack and aborts the process with . Because this is a stack-overflow abort rather than a , it cannot be caught with : any service that parses untrusted PDF input with lopdf can be crashed by a ~21 KB file, resulting in a denial of service. Confirmed on lopdf 0.41.0 and earlier; fixed in 0.42.0. Default configuration, no features changed. ## Proof of concept An equivalent PoC is a minimal PDF whose Catalog value is . ## Suggested fix Enforce a maximum object-nesting depth in the parser and return an instead of recursing without bound.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • crates.io lopdf0 → 0.42.0
  • rust lopdf< 0.42.0

How to fix GHSA-6fj4-rcr3-r7rr

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for GHSA-6fj4-rcr3-r7rr. A missing EPSS score is not a low risk. Compare lopdf has a stack with the linked advisory before you change production.

Which versions are affected?

Compare what you have installed with 0 → 0.42.0, < 0.42.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-1124. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 16, 2026 · GitHub Advisory Database

    Detected

    (and the other entry points) parses nested PDF arrays and dictionaries with unbounded recursion. A small crafted PDF whose Catalog contains a deeply nested array ( , on the order of 10,000 levels) exhausts the call stack and aborts the process with . Because this is a stack-overflow abort rather than a , it cannot be caught with : any service that parses untrusted PDF input with lopdf can be crash

  2. Oct 16, 2026 · GitHub Advisory Database

    Fix available

    lopdf fixed in 0.42.0

  3. Oct 16, 2026 · GitHub Advisory Database

    Fix available

    lopdf fixed in 0.42.0

  4. Oct 16, 2026 · GitHub Advisory Database

    Updated

    (and the other entry points) parses nested PDF arrays and dictionaries with unbounded recursion. A small crafted PDF whose Catalog contains a deeply nested array ( , on the order of 10,000 levels) exhausts the call stack and aborts the process with . Because this is a stack-overflow abort rather than a , it cannot be caught with : any service that parses untrusted PDF input with lopdf can be crash

  5. Oct 17, 2026 · GitHub Advisory Database

    Updated

    (and the other entry points) parses nested PDF arrays and dictionaries with unbounded recursion. A small crafted PDF whose Catalog contains a deeply nested array ( , on the order of 10,000 levels) exhausts the call stack and aborts the process with . Because this is a stack-overflow abort rather than a , it cannot be caught with : any service that parses untrusted PDF input with lopdf can be crash

Sources

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.