How severe is CVE-2026-27888?

CVE-2026-27888 has a CVSS 3.x base score of 7.5, rated high 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 high.

Is CVE-2026-27888 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27888?

CVE-2026-27888 affects Pypdf Project Pypdf. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27888?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-27888 have an EU (EUVD) identifier?

Yes. CVE-2026-27888 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8791.

When was CVE-2026-27888 published?

CVE-2026-27888 was published on 2026-02-26 and last updated on 2026-06-17.

CVE-2026-27888

CVE-2026-27888 is a high-severity vulnerability in Pypdf Project Pypdf with a CVSS 3.x base score of 7.5. 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: High (CVSS 3.x base score 7.5)
CVSS v4: 6.6
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8791
Weakness: CWE-400
Affected product: Pypdf Project Pypdf
Published: 2026-02-26
Last modified: 2026-06-17

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.

Frequently asked questions

What is CVE-2026-27888?: pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
How severe is CVE-2026-27888?: CVE-2026-27888 has a CVSS 3.x base score of 7.5, rated high 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 high.
Is CVE-2026-27888 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27888?: CVE-2026-27888 affects Pypdf Project Pypdf. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27888?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-27888 have an EU (EUVD) identifier?: Yes. CVE-2026-27888 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8791.
When was CVE-2026-27888 published?: CVE-2026-27888 was published on 2026-02-26 and last updated on 2026-06-17.

References

Affected products (1)

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

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