CVE-2026-19643

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 74% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An out-of-bounds read issue in the Base64 decoder in Amazon aws-sdk-cpp before 1.11.862, on some platforms, might allow a remote authenticated user to crash an application that processes crafted Base64-encoded input.

To remediate this issue, users should upgrade to version 1.11.862.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 18, 2026

Advisory Details (1)

Auto-updated Aug 12, 2026
No patch confirmed yet.
generic

CVE-2026-19642 & CVE-2026-19643 - Memory-safety issues in the Base64 decoder in the AWS SDK for C++

https://aws.amazon.com/security/security-bulletins/2026-080-aws/

Vendor Advisories for CVE-2026-19643(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 14× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-19 17:03 UTCEPSS rescore
  2. 2026-08-18 14:52 UTCEG score recompute
  3. 2026-08-18 13:48 UTCEPSS rescore
  4. 2026-08-17 14:39 UTCEG score recompute
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 14:24 UTCEG score recompute
  8. 2026-08-16 02:14 UTCEPSS rescore
  9. 2026-08-15 14:08 UTCEG score recompute
  10. 2026-08-15 01:30 UTCEPSS rescore
  11. 2026-08-14 13:52 UTCEG score recompute
  12. 2026-08-13 22:00 UTCEPSS rescore
  13. 2026-08-13 13:36 UTCEG score recompute
  14. 2026-08-13 12:47 UTCEG score recompute
  15. 2026-08-12 20:19 UTCEG score recompute
  16. 2026-08-12 19:46 UTCEG score recompute
  17. 2026-08-12 19:45 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-19643?
CVE-2026-19643 is a medium vulnerability published on August 12, 2026. An out-of-bounds read issue in the Base64 decoder in Amazon aws-sdk-cpp before 1.11.862, on some platforms, might allow a remote authenticated user to crash an application that processes crafted Base64-encoded input. To remediate this issue, users should upgrade to version 1.11.862.
When was CVE-2026-19643 disclosed?
CVE-2026-19643 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-19643 actively exploited?
CVE-2026-19643 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 73.0% of all scored CVEs.
What is the CVSS score of CVE-2026-19643?
CVE-2026-19643 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-19643?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-19643, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-19643

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Is Your Infrastructure Affected by CVE-2026-19643?

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