How severe is CVE-2026-28351?

CVE-2026-28351 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-28351 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-28351?

CVE-2026-28351 affects Pypdf Project Pypdf. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-28351?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-28351 have an EU (EUVD) identifier?

Yes. CVE-2026-28351 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9070.

When was CVE-2026-28351 published?

CVE-2026-28351 was published on 2026-02-27 and last updated on 2026-06-17.

CVE-2026-28351

CVE-2026-28351 is a medium-severity vulnerability in Pypdf Project Pypdf with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 6.9
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9070
Weakness: CWE-400
Affected product: Pypdf Project Pypdf
Published: 2026-02-27
Last modified: 2026-06-17

Description

pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.4, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter. This has been fixed in pypdf 6.7.4. As a workaround, consider applying the changes from PR #3664.

Frequently asked questions

What is CVE-2026-28351?: pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.4, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter. This has been fixed in pypdf 6.7.4. As a workaround, consider applying the changes from PR #3664.
How severe is CVE-2026-28351?: CVE-2026-28351 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-28351 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-28351?: CVE-2026-28351 affects Pypdf Project Pypdf. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-28351?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-28351 have an EU (EUVD) identifier?: Yes. CVE-2026-28351 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9070.
When was CVE-2026-28351 published?: CVE-2026-28351 was published on 2026-02-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*

More vulnerabilities in Pypdf Project Pypdf

CVE-2026-33699 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an…
CVE-2026-27888 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can…
CVE-2026-27628 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to 6.7.2, an attacker who uses this vulnerability can…
CVE-2025-62708 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to version 6.1.3, an attacker who uses this…
CVE-2025-62707 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to version 6.1.3, an attacker who uses this…
CVE-2025-55197 — High (CVSS 7.5): pypdf is a free and open-source pure-python PDF library. Prior to version 6.0.0, an attacker can craft a PDF which…

All CVEs affecting Pypdf Project Pypdf →

Other CWE-400 (Uncontrolled Resource Consumption) vulnerabilities

CVE-2026-46775 — Critical (CVSS 9.9): Vulnerability in Oracle REST Data Services (component: Core). Supported versions that are affected are 24.2.0-26.1.0.…
CVE-2025-61303 — Critical (CVSS 9.8): Hatching Triage Sandbox Windows 10 build 2004 (2025-08-14) and Windows 10 LTSC 2021(2025-08-14) contains a…
CVE-2025-43193 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.6, macOS Sonoma 14.7.7,…
CVE-2025-24269 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4. An app may be able to…
CVE-2025-24264 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in Safari 18.4, iOS 18.4 and iPadOS 18.4,…
CVE-2025-24260 — Critical (CVSS 9.8): The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.4, macOS Sonoma 14.7.5,…

Browse all CWE-400 (Uncontrolled Resource Consumption) vulnerabilities →