AWS SDK for PHP's S3 Encryption Client has a Key Commitment Issue

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.0 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2025-14761: 0.21% estimated exploitation activity in the next 30 days; percentile 11.41 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary S3 Encryption Client for PHP is an open-source client-side encryption library used to facilitate writing and reading encrypted records to S3. When the encrypted data key (EDK) is stored in an "Instruction File" instead of S3's metadata record, the EDK is exposed to an "Invisible Salamanders" attack (https://eprint.iacr.org/2019/016), which could allow the EDK to be replaced with a new key. Impact Background - Key Commitment There is a cryptographic property whereby under certain conditions, a single ciphertext can be decrypted into 2 different plaintexts by using different encryption keys. To address this issue, strong encryption schemes use what is known as "key commitment", a process by which an encrypted message can only be decrypted by one key; the key used to originally encrypt the message. In older versions of S3EC, when customers are also using a feature called "Instruction File" to store EDKs, key commitment is not implemented because multiple EDKs could be associated…

Published by the source

18 Dec 2025, 18:52 UTC

Last modified by the source

20 Dec 2025, 05:31 UTC

Source last checked

26 Oct 2026, 14:35 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x8cp-jf6f-r4xh

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# Patch Next advisory brief: CVE-2025-14761

Advisory: AWS SDK for PHP's S3 Encryption Client has a Key Commitment Issue
IDs: CVE-2025-14761, GHSA-x8cp-jf6f-r4xh
Record: https://patchnext.com/advisories/cve-2025-14761 (revision 1, source checked 26 Oct 2026, 14:35 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: aws/aws-sdk-php 3.368.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist aws/aws-sdk-php: affected < 3.368.0; fixed in 3.368.0

## Suggested inspection (read-only)
- Packagist aws/aws-sdk-php: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on aws/aws-sdk-php.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x8cp-jf6f-r4xh (GitHub-reviewed advisory GHSA-x8cp-jf6f-r4xh lists affected ranges: Packagist aws/aws-sdk-php >=0 <3.368.0)

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