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Fencer Vulns
medium 5.3

CVE-2021-25786 json

An issue was discovered in QPDF version 10.0.4, allows remote attackers to execute arbitrary code via crafted .pdf file to Pl_ASCII85Decode…

published 2023-08-11 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12669

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

An issue was discovered in QPDF version 10.0.4, allows remote attackers to execute arbitrary code via crafted .pdf file to Pl_ASCII85Decoder::write parameter in libqpdf.

Patch / fix

  • qpdf Debian 14, Debian 13, Debian 12 10.1.0-1

debian advisories DEBIAN-CVE-2021-25786

  • qpdf Ubuntu 18.04 LTS 8.0.2-3ubuntu0.1
  • qpdf Ubuntu 20.04 LTS 9.1.1-1ubuntu0.1
  • qpdf Ubuntu Pro 16.04 LTS 8.0.2-3~16.04.1+esm1

ubuntu advisories UBUNTU-CVE-2021-25786

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-25786 updated cvss 5.3

qpdf: Heap use after free in Pl_ASCII85Decoder::write

  • Red Hat Enterprise Linux 7 qpdf, qpdf-libs
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 qpdf, qpdf-libs Red Hat Enterprise Linux 9 qpdf, qpdf-libs
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/qpdf/qpdf/issues/492 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.