Utils.readChallengeTx does not verify the server account signature

Exploitation

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

CVSS

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

EPSS

• CVE-2021-32738: 0.51% estimated exploitation activity in the next 30 days; percentile 43.82 (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.

The Utils.readChallengeTx function used in SEP-10 Stellar Web Authentication states in its function documentation that it reads and validates the challenge transaction including verifying that the serverAccountID has signed the transaction. The function does not verify that the server has signed the transaction and has been fixed so that it does in v8.2.3. Applications that also used Utils.verifyChallengeTxThreshold or Utils.verifyChallengeTxSigners to verify the signatures including the server signature on the challenge transaction are unaffected as those functions verify the server signed the transaction. Applications calling Utils.readChallengeTx should update to v8.2.3 to ensure that the challenge transaction is completely valid and signed by the server creating the challenge transaction.

Published by the source

2 Jul 2021, 19:20 UTC

Last modified by the source

8 Jul 2026, 06:29 UTC

Source last checked

26 Oct 2026, 12:16 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6cgh-hjpw-q3gq

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-6cgh-hjpw-q3gq

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# Patch Next advisory brief: CVE-2021-32738

Advisory: Utils.readChallengeTx does not verify the server account signature
IDs: CVE-2021-32738, GHSA-6cgh-hjpw-q3gq
Record: https://patchnext.com/advisories/cve-2021-32738 (revision 2, source checked 26 Oct 2026, 12:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: stellar-sdk 8.2.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm stellar-sdk: affected < 8.2.3; fixed in 8.2.3

## Suggested inspection (read-only)
- `npm ls stellar-sdk --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 stellar-sdk.
- 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://osv.dev/vulnerability/GHSA-6cgh-hjpw-q3gq (OSV record GHSA-6cgh-hjpw-q3gq lists affected ranges: npm stellar-sdk >=0 <8.2.3 (fixed))
- Verified: https://github.com/advisories/GHSA-6cgh-hjpw-q3gq (GitHub-reviewed advisory GHSA-6cgh-hjpw-q3gq lists affected ranges: npm stellar-sdk >=0 <8.2.3)

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