CVE-2026-33123

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 72% 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, nvd
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
29%
KEV
Not listed

Published

March 20, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 4, 2026
Patch available. Sources: github_pr, github_release, github.
github Patch Available

Inefficient decoding of array-based streams · Advisory · py-pdf/pypdf · GitHub

https://github.com/py-pdf/pypdf/security/advisories/GHSA-qpxp-75px-xjcp
github_release Patch Available

Version 6.9.1, 2026-03-17

Patch available: py-pdf/pypdf 6.9.1

https://github.com/py-pdf/pypdf/releases/tag/6.9.1
github_pr Patch Available

SEC: Improve performance and limit length of array-based content streams

Patch available: py-pdf/pypdf 6.9.1 (PR #3686 merged 2026-03-17)

https://github.com/py-pdf/pypdf/pull/3686

Affected Packages

(6 across 5 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
pypdf3.17.4-1 ... 6.9.2-2 (14 versions)——
pypdf22.12.1-3, 2.12.1-3+deb12u1, 2.12.1-4——
Debian:11(1)
PackageVulnerable rangeFixed inDependents
pypdf21.26.0-4 ... 2.9.0-1 (24 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
pypdf5.4.0-1, 6.9.0-1, 6.9.2-1, 6.9.2-2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
pypdf5.4.0-1, 6.9.0-16.9.2-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
pypdf1.0 ... 6.9.0 (96 versions)6.9.1—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 17:08 UTCOSV refresh
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-09-01 04:39 UTCEPSS rescore
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 37 more
  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 11:02 UTCEG score recompute
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 07:13 UTCEG score recompute
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 00:04 UTCEG score recompute
  16. 2026-08-12 13:50 UTCEPSS rescore
  17. 2026-08-12 02:17 UTCEG score recompute
  18. 2026-08-11 04:25 UTCEG score recompute
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 04:33 UTCEG score recompute
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-09 06:46 UTCEG score recompute
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-07 17:15 UTCEG score recompute
  25. 2026-08-06 13:46 UTCEPSS rescore
  26. 2026-08-06 01:28 UTCEG score recompute
  27. 2026-08-05 19:17 UTCEPSS rescore
  28. 2026-08-04 15:10 UTCEPSS rescore
  29. 2026-08-04 10:38 UTCEPSS rescore
  30. 2026-08-04 00:36 UTCEG score recompute
  31. 2026-08-03 10:36 UTCEPSS rescore
  32. 2026-08-02 16:13 UTCEG score recompute
  33. 2026-08-02 02:27 UTCEPSS rescore
  34. 2026-08-01 04:16 UTCEPSS rescore
  35. 2026-07-30 16:28 UTCEPSS rescore
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-27 14:35 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-33123?
CVE-2026-33123 is a medium vulnerability published on March 20, 2026. pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.
When was CVE-2026-33123 disclosed?
CVE-2026-33123 was first published in the National Vulnerability Database on March 20, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33123 actively exploited?
CVE-2026-33123 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 71.4% of all scored CVEs.
What is the CVSS score of CVE-2026-33123?
CVE-2026-33123 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-33123?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-33123, 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

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