VulnerabilityPublished 2 Mar 2026

CVE-2026-3337: AWS-LC · (Observable Timing Discrepancy)

Affects AWS-LCSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 1.69.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.0% chance of exploitation in 30 days – higher than 65% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.69.0, 3.2.0

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade AWS-LC to 1.69.0; AWS-LC-FIPS to 3.2.0.

Affected software

Product	Affected	Fixed in
AWSAWS-LC	Affected >=1.21.0 <1.69.0	Fixed in 1.69.0
AWSAWS-LC-FIPS	Affected >=3.0.0 <3.2.0	Fixed in 3.2.0
GitHubaws/aws-lc`pkg:github/aws/aws-lc`Other threats	Affected =1.21.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-3337, organizations should promptly upgrade AWS-LC to version 1.69.0 or later, where the timing discrepancy has been resolved. Developers should audit their applications to identify any direct usage of AWS-LC, particularly the EVP_aes_128_ccm, EVP_aes_192_ccm, and EVP_aes_256_ccm APIs, and ensure they are linked against the patched library version. Implementing constant-time cryptographic operations is critical; thus, reviewing and testing cryptographic code for timing side channels is recommended. Network-level protections such as rate limiting and anomaly detection can help reduce the feasibility of timing attacks by limiting attacker query volume and precision. Additionally, organizations should monitor for unusual traffic patterns that may indicate timing analysis attempts. Security teams should update threat models to include timing side-channel risks and educate developers on secure cryptographic implementation practices. Finally, maintain awareness of AWS-LC updates and advisories to promptly address future vulnerabilities.

Description

Observable timing discrepancy in AES-CCM decryption in AWS-LC allows an unauthenticated user to potentially determine authentication tag validity via timing analysis. The impacted implementations are through the EVP CIPHER API: EVP_aes_128_ccm, EVP_aes_192_ccm, and EVP_aes_256_ccm. Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.

Impact

The primary impact of CVE-2026-3337 is on the integrity of encrypted communications that use AES-CCM via AWS-LC. An attacker capable of measuring decryption timing can potentially confirm the validity of authentication tags, which may facilitate cryptographic attacks such as forgery or plaintext recovery over time. While confidentiality and availability are not directly compromised, the integrity breach can undermine trust in secure messaging or data protection mechanisms. Organizations using AWS-LC in their applications, especially those handling sensitive or regulated data, risk exposure to subtle cryptographic attacks that could lead to data manipulation or unauthorized message acceptance. Since exploitation requires only network access and no authentication, the attack surface includes any exposed services using vulnerable AWS-LC versions. However, the high attack complexity and absence of known exploits reduce immediate risk. The vulnerability does not affect AWS-managed services, limiting impact on customers relying solely on AWS cloud services. Nonetheless, organizations embedding AWS-LC in their software stacks must address this to maintain cryptographic robustness and compliance.

CWE-208Observable Timing Discrepancy (opens in a new tab)
Base weakness
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Cross-Domain Search Timing (opens in a new tab)
Application Fingerprinting (opens in a new tab)
System Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Mar 2026, 17:29 UTC

WeaknessesCWE-208

Technical details

References

Community reviews

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