CVE-2026-3337Network attack vector

Tag-validity disclosure via variable-time comparison

Published Mar 2, 2026 · Updated Mar 2, 2026

An AES-CCM timing side channel in AWS-LC 1.21.0 through 1.68.0 and AWS-LC-FIPS 3.0.0 through 3.1.0 allows remote attackers to infer tag validity. The EVP_aes_128_ccm, EVP_aes_192_ccm, and EVP_aes_256_ccm decrypt paths use OPENSSL_memcmp instead of constant-time CRYPTO_memcmp to verify supplied tags. The caller must expose repeated AES-CCM decryptions and observable response timing; successful analysis reveals whether submitted tags are valid.

CVSS severity8.2
High
EPSS probability1.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An AES-CCM timing side channel in AWS-LC 1.21.0 through 1.68.0 and AWS-LC-FIPS 3.0.0 through 3.1.0 allows remote attackers to infer tag validity. The EVP_aes_128_ccm, EVP_aes_192_ccm, and EVP_aes_256_ccm decrypt paths use OPENSSL_memcmp instead of constant-time CRYPTO_memcmp to verify supplied tags. The caller must expose repeated AES-CCM decryptions and observable response timing; successful analysis reveals whether submitted tags are valid.

The record

CVE
CVE-2026-3337
Published
Mar 2, 2026
Updated
Mar 2, 2026
Vendor
Amazon Web Services
Product
AWS-LC
Classifications
CWE-208
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.21.0 <1.69.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Amazon Web Services · AWS-LCversion=1.21.0 <1.69.0
Amazon Web Services · AWS-LC-FIPSversion=3.0.0 <3.2.0

Published CVSS scores

8.2Amazon Web ServicesCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
5.9Amazon Web ServicesCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-208Observable Timing Discrepancy

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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