Description
In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild have recursive calls for a long time, which allows remote attackers to cause a denial of service via a crafted PDF file.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | qpdf | 9.0.0-1 | — |
| Debian 13 | qpdf | 9.0.0-1 | — |
| Debian 12 | qpdf | 9.0.0-1 | — |
| Debian 10 | qpdf | 8.4.0-2+deb10u1 | DLA-3548-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | qpdf | 9.1.1-1ubuntu0.1 | USN-5026-1 |
| Ubuntu 18.04 LTS | qpdf | 8.0.2-3ubuntu0.1 | USN-5026-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | qpdf | 8.0.2-3~16.04.1+esm1 | USN-5026-2 |
Advisories 3
- USN-5026-2 qpdf vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-5026-1 qpdf vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-3548-1 qpdf - security update Debian Security (DSA / DLA) · Mar 9, 2026