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OpenAdvisories
High ALAS2-2026-3992 3 CVEs

Important: openssl security update (Amazon Linux 2)

Published Oct 12, 2026 · Updated Oct 12, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-84782: A flaw was found in OpenSSL. The Datagram Transport Layer Security (DTLS) retransmission mechanism fails to properly handle handshake message writes that are suspended before completion. A remote attacker could exploit this vulnerability during handshake message retransmission, causing OpenSSL to read past the message buffer or overwrite internal state required to resume writing. This issue can result in information disclosure through out-of-bounds memory reads or cause a Denial of Service (DoS) by crashing the process. 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. CVE-2026-35189: Issue summary: A certificate with many nameRelativeToCRLIssuer CRL distribution points causes disproportionate heap growth when OpenSSL caches X.509 extensions. Impact summary: Receiving a crafted certificate from a malicious peer can lead to significant memory pressure and possible Denial of Service in clients or in servers that solicit client certificates. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: A certificate or a set of certificates that fits under the limit for size of certificates accepted from the peer (~100 KiB) can result in allocation of several hundred MiB of resident memory on the receiving side during a normal TLS handshake. This may be enough to crash the client or server, if multiple concurrent connections lead to similarly large memory allocations. The fix postpones processing of the CRL distribution points extensions in certificates to the time when the processed value is required for CRL processing. This avoids keeping large memory allocations for a long time when such certificates are received. FIPS impact: no The affected code is outside the FIPS module boundary.

Fixed packages 6

ReleasePackageFixed in
Amazon Linux · 2 openssl 1:1.0.2k-24.amzn2.0.23
Amazon Linux · 2 openssl-debuginfo 1:1.0.2k-24.amzn2.0.23
Amazon Linux · 2 openssl-devel 1:1.0.2k-24.amzn2.0.23
Amazon Linux · 2 openssl-libs 1:1.0.2k-24.amzn2.0.23
Amazon Linux · 2 openssl-perl 1:1.0.2k-24.amzn2.0.23
Amazon Linux · 2 openssl-static 1:1.0.2k-24.amzn2.0.23

Vulnerabilities 3

  • High 8.2

    DTLS Retransmits Handshake Messages From a Stale Buffer Offset

    Issue summary: The DTLS retransmission logic does not correctly handle a handshake message write that is suspended part-way through. The retransmitted message can be read past the message buffer and the retransmission overwrites the internal state the suspend…

  • Medium 5.3

    Excessive Memory Allocation in Relative CRLDP Processing

    Issue summary: A certificate with many nameRelativeToCRLIssuer CRL distribution points causes disproportionate heap growth when OpenSSL caches X.509 extensions. Impact summary: Receiving a crafted certificate from a malicious peer can lead to significant memo…

  • Low 3.7

    Timing Side-Channel in Scalar Multiplication for Non-NIST EC Curves

    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 me…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-35189.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-54872.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-84782.html