CVE-2026-88361

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-24. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
65
EG Risk 65/100CISA SSVC

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
EPSS PROB
0.4%
EPSS %ILE
35th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 24, 2026

Last Modified

September 25, 2026

Advisory Details (3)

Auto-updated Sep 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

Signed integer overflow in BuildPageLabelRec() while parsing PDF PageLabels /Nums key INT_MAX (CWE-190) -> UBSAN SIGILL · Issue #5952 · sumatrapdfreader/sumatrapdf · GitHub

https://github.com/sumatrapdfreader/sumatrapdf/issues/5952
github_commit

commit 8b999ff1bf0a (haimag/sumatrapdf)

Fix landed in haimag/sumatrapdf commit 8b999ff1bf0a — awaiting tagged release

https://github.com/haimag/sumatrapdf/commit/8b999ff1bf0a8df244e75440682a3fd9a038eb2d
github_commit

commit b22a8c71ddc9 (chenjiefeng2001/sumatrapdf_folked)

Fix landed in chenjiefeng2001/sumatrapdf_folked commit b22a8c71ddc9 — awaiting tagged release

https://github.com/chenjiefeng2001/sumatrapdf_folked/commit/b22a8c71ddc9de80ece5f88d14b434c20fee912e

Vendor Advisories for CVE-2026-88361(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 26× in last 7d / 42× 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. 2026-10-04 02:48 UTCGHSA enrichment
  2. 2026-10-03 15:50 UTCEG score recompute
  3. 2026-10-03 15:50 UTCGHSA enrichment
  4. 2026-10-03 04:50 UTCEG score recompute
  5. 2026-10-03 04:50 UTCGHSA enrichment
  6. 2026-10-02 17:52 UTCGHSA enrichment
  7. 2026-10-02 06:55 UTCGHSA enrichment
  8. 2026-10-01 19:57 UTCEG score recompute
  9. 2026-10-01 19:57 UTCGHSA enrichment
  10. 2026-10-01 19:51 UTCEPSS rescore
  11. 2026-10-01 08:59 UTCGHSA enrichment
  12. 2026-09-30 22:02 UTCEG score recompute
  13. 2026-09-30 22:01 UTCGHSA enrichment
  14. 2026-09-30 15:04 UTCEPSS rescore
  15. 2026-09-30 11:04 UTCGHSA enrichment
  16. 2026-09-30 00:06 UTCEG score recompute
  17. 2026-09-30 00:06 UTCGHSA enrichment
  18. 2026-09-29 10:43 UTCGHSA enrichment
  19. 2026-09-28 23:38 UTCEG score recompute
  20. 2026-09-28 23:38 UTCGHSA enrichment
  21. 2026-09-28 13:52 UTCEPSS rescore
  22. 2026-09-28 12:40 UTCGHSA enrichment
  23. 2026-09-28 01:42 UTCGHSA enrichment
  24. 2026-09-27 14:40 UTCEG score recompute
  25. 2026-09-27 14:40 UTCGHSA enrichment
Show 17 more
  1. 2026-09-27 13:48 UTCEPSS rescore
  2. 2026-09-27 03:43 UTCGHSA enrichment
  3. 2026-09-26 16:43 UTCEG score recompute
  4. 2026-09-26 16:43 UTCGHSA enrichment
  5. 2026-09-26 15:59 UTCEPSS rescore
  6. 2026-09-26 05:42 UTCGHSA enrichment
  7. 2026-09-26 05:41 UTCEG score recompute
  8. 2026-09-26 05:41 UTCGHSA enrichment
  9. 2026-09-25 18:40 UTCEG score recompute
  10. 2026-09-25 18:40 UTCGHSA enrichment
  11. 2026-09-25 18:15 UTCEG score recompute▲ 7.50
  12. 2026-09-25 18:15 UTCGHSA enrichment
  13. 2026-09-25 18:14 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  14. 2026-09-24 21:16 UTCGHSA enrichment
  15. 2026-09-24 16:30 UTCNVD update
  16. 2026-09-24 15:32 UTCEG score recompute
  17. 2026-09-24 15:31 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88361?
CVE-2026-88361 is a high vulnerability published on September 24, 2026. SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.
When was CVE-2026-88361 disclosed?
CVE-2026-88361 was first published on September 24, 2026, with the most recent update on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88361 actively exploited?
CVE-2026-88361 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (35th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88361?
CVE-2026-88361 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-88361?
An upstream fix for CVE-2026-88361 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-88361 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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