How severe is CVE-2026-54872?

CVE-2026-54872 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-54872 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-54872?

CVE-2026-54872 affects Openssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-54872?

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

When was CVE-2026-54872 published?

CVE-2026-54872 was published on 2026-09-29 and last updated on 2026-10-08.

CVE-2026-54872

CVE-2026-54872 is a low-severity vulnerability in Openssl with a CVSS 3.x base score of 3.7. 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-208.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-208
Affected product: Openssl
Published: 2026-09-29
Last modified: 2026-10-08

Description

Issue summary: The generic elliptic-curve scalar multiplication used for ECDSA and SM2 signature operations with curves that do not have a dedicated implementation leaks information about the secret nonce through timing. Impact summary: An attacker able to measure signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: The generic elliptic-curve scalar multiplication used for curves that do not have a dedicated constant-time implementation pads the secret scalar with non-constant-time BIGNUM operations, so the time taken depends on the value of the secret scalar derived from the ECDSA and SM2 nonce. The leak is very small; observing it requires a large number of measurements. The effect is largest for curves whose group order lies on a machine-word boundary, such as brainpoolP384r1. Applications using ECDSA signing over the Brainpool and other generic prime curves, and SM2 signing on platforms that use the generic implementation, are vulnerable to this issue. The NIST curves P-256, P-384 and P-521 use dedicated constant-time implementations and are not affected. FIPS Impact: no The FIPS modules are not affected: the approved NIST curves used in the FIPS provider have dedicated constant-time implementations and do not use the affected code path.

Frequently asked questions

What is CVE-2026-54872?: Issue summary: The generic elliptic-curve scalar multiplication used for ECDSA and SM2 signature operations with curves that do not have a dedicated implementation leaks information about the secret nonce through timing. Impact summary: An attacker able to measure signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: The generic elliptic-curve scalar multiplication used for curves that do not have a dedicated constant-time implementation pads the secret scalar with non-constant-time BIGNUM operations, so the time taken depends on the value of the secret scalar derived from the ECDSA and SM2 nonce. The leak is very small; observing it requires a large number of measurements. The effect is largest for curves whose group order lies on a machine-word boundary, such as brainpoolP384r1. Applications using ECDSA signing over the Brainpool and other generic prime curves, and SM2 signing on platforms that use the generic implementation, are vulnerable to this issue. The NIST curves P-256, P-384 and P-521 use dedicated constant-time implementations and are not affected. FIPS Impact: no The FIPS modules are not affected: the approved NIST curves used in the FIPS provider have dedicated constant-time implementations and do not use the affected code path.
How severe is CVE-2026-54872?: CVE-2026-54872 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-54872 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54872?: CVE-2026-54872 affects Openssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-54872?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-54872 published?: CVE-2026-54872 was published on 2026-09-29 and last updated on 2026-10-08.

References

Affected products (1)

cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

159.223.95.100 (ipv4-addr)
194.50.173.43 (ipv4-addr)
181.224.200.6 (ipv4-addr)
144.202.0.81 (ipv4-addr)
78.189.135.34 (ipv4-addr)
42.192.101.199 (ipv4-addr)
93.58.255.46 (ipv4-addr)
41.223.107.27 (ipv4-addr)