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No exploitation reportedFix available

CVE-2026-28804

No exploitation reported by the sources we read.

  • Published2026-03-06
  • Fixed in6.7.5
  • WeaknessCWE-407

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5.

Timeline

dates in UTC
  1. 2026-03-0607:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-28804?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-28804?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Pypdf project pypdf
BranchAffectedFixed in
6.7< 6.7.56.7.5

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-28804 Red Hat Product Security6 known affected

    pypdf: pypdf: Denial of Service via crafted PDF with ASCIIHexDecode filter

    openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 as a component of OpenShift Lightspeed · openshift-lightspeed/lightspeed-ocp-rag-rhel9 as a component of OpenShift Lightspeed · openshift-lightspeed/lightspeed-service-api-rhel9 as a component of OpenShift Lightspeed · +3 more

Full record on NVD

Fix

  1. Update Pypdf project pypdf to 6.7.5
  2. Workaround from the vendor Red Hat Product Security CVE-2026-28804 · 6 productsTo mitigate this issue, avoid processing untrusted PDF documents with applications that use the pypdf library. If processing untrusted PDFs is unavoidable, consider sandboxing the application responsible for PDF processing to limit potential resource exhaustion.
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-28804 · 6 productsFix deferred

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2026-03-06
  • OpenCVESSVC decisionnone—
  • CNACVSS 4.06.9read 2026-10-23
  • NVDCVSS 3.15.3read 2026-10-23
  • CNAweakness (CWE)CWE-407read 2026-10-23
  • FIRST EPSSEPSS score0.5 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-03-06
Last Modified
2026-06-17
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-28804?

pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5.

Is CVE-2026-28804 actively exploited?

Active exploitation of CVE-2026-28804 has not been confirmed. Its EPSS score was 0.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-28804?

CVE-2026-28804 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Running pypdf? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

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