How severe is CVE-2009-0591?

CVE-2009-0591 has a CVSS 2.0 base score of 2.6, rated low severity.

Is CVE-2009-0591 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0591?

CVE-2009-0591 primarily affects Openssl. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0591?

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

When was CVE-2009-0591 published?

CVE-2009-0591 was published on 2009-03-27 and last updated on 2026-06-16.

CVE-2009-0591

CVE-2009-0591 is a low-severity vulnerability in Openssl with a CVSS 2.0 base score of 2.6. 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-287.

Key facts

Severity: Low (CVSS 2.0 base score 2.6)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Openssl
Published: 2009-03-27
Last modified: 2026-06-16

Description

The CMS_verify function in OpenSSL 0.9.8h through 0.9.8j, when CMS is enabled, does not properly handle errors associated with malformed signed attributes, which allows remote attackers to repudiate a signature that originally appeared to be valid but was actually invalid.

Frequently asked questions

What is CVE-2009-0591?: The CMS_verify function in OpenSSL 0.9.8h through 0.9.8j, when CMS is enabled, does not properly handle errors associated with malformed signed attributes, which allows remote attackers to repudiate a signature that originally appeared to be valid but was actually invalid.
How severe is CVE-2009-0591?: CVE-2009-0591 has a CVSS 2.0 base score of 2.6, rated low severity.
Is CVE-2009-0591 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0591?: CVE-2009-0591 primarily affects Openssl. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0591?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0591 published?: CVE-2009-0591 was published on 2009-03-27 and last updated on 2026-06-16.

References

Affected products (3)

cpe:2.3:a:openssl:openssl:0.9.8h:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:0.9.8i:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:0.9.8j:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
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