How severe is CVE-2020-26535?

CVE-2020-26535 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-26535 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-26535?

CVE-2020-26535 primarily affects Foxitsoftware Foxit Reader. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-26535?

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

When was CVE-2020-26535 published?

CVE-2020-26535 was published on 2020-10-02 and last updated on 2026-06-17.

CVE-2020-26535

CVE-2020-26535 is a critical-severity vulnerability in Foxitsoftware Foxit Reader with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Foxitsoftware Foxit Reader
Published: 2020-10-02
Last modified: 2026-06-17

Description

An issue was discovered in Foxit Reader and PhantomPDF before 10.1. If TslAlloc attempts to allocate thread local storage but obtains an unacceptable index value, V8 throws an exception that leads to a write access violation (and read access violation).

Frequently asked questions

What is CVE-2020-26535?: An issue was discovered in Foxit Reader and PhantomPDF before 10.1. If TslAlloc attempts to allocate thread local storage but obtains an unacceptable index value, V8 throws an exception that leads to a write access violation (and read access violation).
How severe is CVE-2020-26535?: CVE-2020-26535 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-26535 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26535?: CVE-2020-26535 primarily affects Foxitsoftware Foxit Reader. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-26535?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-26535 published?: CVE-2020-26535 was published on 2020-10-02 and last updated on 2026-06-17.

References

https://www.foxitsoftware.com/support/security-bulletins.html

Affected products (2)

cpe:2.3:a:foxitsoftware:foxit_reader:*:*:*:*:*:*:*:*
cpe:2.3:a:foxitsoftware:phantompdf:*:*:*:*:*:*:*:*

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