CVE-2026-54531

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.5 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 98% 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
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 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. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

CVSS v3
5.5
EG Score
5.5(medium)
EPSS
2.4%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 25, 2026

Advisory Details (3)

Auto-updated Jun 22, 2026
Patch available. Sources: github_pr, github_release, github.
github Patch Available

Possible infinite loop when processing outlines/bookmarks in writer · Advisory · py-pdf/pypdf · GitHub

https://github.com/py-pdf/pypdf/security/advisories/GHSA-m2v9-299j-rv96
github_release Patch Available

Version 6.13.0, 2026-06-05

Patch available: py-pdf/pypdf 6.13.0

https://github.com/py-pdf/pypdf/releases/tag/6.13.0
github_pr Patch Available

SEC: Avoid infinite loops for outlines and text extraction

Patch available: py-pdf/pypdf 6.13.0 (PR #3830 merged 2026-06-05)

https://github.com/py-pdf/pypdf/pull/3830

Vendor Advisories for CVE-2026-54531(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
pypdf1.0 ... 6.9.2 (105 versions)6.13.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 32× 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. 2026-07-06 23:15 UTCEG score recompute
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-05 08:44 UTCEG score recompute
  5. 2026-07-04 09:21 UTCEG score recompute
  6. 2026-07-04 06:31 UTCEPSS rescore
  7. 2026-07-04 06:31 UTCEPSS rescore
  8. 2026-07-03 08:20 UTCEG score recompute
  9. 2026-07-02 09:35 UTCEG score recompute
  10. 2026-07-01 10:53 UTCEG score recompute
  11. 2026-06-30 12:10 UTCEG score recompute
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-29 13:29 UTCEG score recompute
  15. 2026-06-28 14:48 UTCEG score recompute
  16. 2026-06-28 14:07 UTCEPSS rescore
  17. 2026-06-28 04:56 UTCEPSS rescore
  18. 2026-06-28 04:56 UTCEPSS rescore
  19. 2026-06-27 16:07 UTCEG score recompute
  20. 2026-06-27 03:08 UTCEPSS rescore
  21. 2026-06-26 17:23 UTCEG score recompute
  22. 2026-06-25 18:41 UTCEG score recompute▼ 1.40
  23. 2026-06-25 17:48 UTCNVD updateCVSS v3 → 5.5
  24. 2026-06-25 13:49 UTCEPSS rescore
  25. 2026-06-24 20:00 UTCEG score recompute
Show 7 more
  1. 2026-06-24 14:05 UTCEPSS rescore
  2. 2026-06-23 21:33 UTCEPSS rescore
  3. 2026-06-23 21:33 UTCEPSS rescore
  4. 2026-06-23 20:24 UTCEG score recompute
  5. 2026-06-22 21:40 UTCEG score recompute▲ 6.90
  6. 2026-06-22 21:37 UTCNVD updateCVSS v3 → 6.9 · CVSS v4 → 6.9
  7. 2026-06-16 14:09 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54531?
CVE-2026-54531 is a medium vulnerability published on June 16, 2026. pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.
When was CVE-2026-54531 disclosed?
CVE-2026-54531 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54531 actively exploited?
CVE-2026-54531 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54531?
CVE-2026-54531 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-54531?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54531, 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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