CVE-2026-77220

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-21. The CNA's CVSS baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting function that stores a pointer to a stack-local buffer in the document dictionary without copying the string value. In multi-threaded or pooled-request environments, attackers or concurrent users can trigger stack memory reuse across requests, causing cross-tenant document content corruption by silently overwriting one caller's dictionary string values with another caller's data.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100CISA 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
34th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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

August 21, 2026

Last Modified

October 1, 2026

Advisory Details (3)

Auto-updated Aug 21, 2026
Patch available. Sources: github_commit, github_release.
generic

PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting | Advisories | VulnCheck

https://www.vulncheck.com/advisories/pdfio-dangling-pointer-via-dictionary-string-formatting
github_release Patch Available

Release v1.6.5 (michaelrsweet/pdfio)

Patch available: michaelrsweet/pdfio v1.6.5

https://github.com/michaelrsweet/pdfio/releases/tag/v1.6.5
github_commit Patch Available

commit 22b9afc800c5 (michaelrsweet/pdfio)

Patch available: michaelrsweet/pdfio v1.6.5 (contains commit 22b9afc800c5)

https://github.com/michaelrsweet/pdfio/commit/22b9afc800c5833f9e851e35938972bd4c76a357

Vendor Advisories for CVE-2026-77220(1)

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

Affected Packages

(3 across 2 ecosystems)
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
ippsample0.0.0~git20220215.f365352-1 ... 0.0~git20220607.72f89b3-1 (8 versions)
  • every version on: no fix on record
—
pdfio1.5.1+dfsg-1 ... 1.6.3+dfsg-2 (7 versions)
  • every version up to 1.6.5+dfsg-1: fixed in 1.6.5+dfsg-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
ippsample0.0.0~git20220215.f365352-1, 0.0.0~git20220215.f365352-2, 0.0~git20220607.72f89b3-1
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 81× 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.

Showing the most recent 100 of 142 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-09 08:01 UTCEG score recompute
  3. 2026-10-09 08:01 UTCGHSA enrichment
  4. 2026-10-08 17:13 UTCEPSS rescore
  5. 2026-10-08 09:29 UTCEG score recompute
  6. 2026-10-08 09:29 UTCGHSA enrichment
  7. 2026-10-07 23:48 UTCEPSS rescore
  8. 2026-10-07 11:03 UTCEG score recompute
  9. 2026-10-07 11:03 UTCGHSA enrichment
  10. 2026-10-06 15:18 UTCEPSS rescore
  11. 2026-10-06 12:38 UTCEG score recompute
  12. 2026-10-06 12:38 UTCGHSA enrichment
  13. 2026-10-05 17:43 UTCEPSS rescore
  14. 2026-10-05 14:12 UTCEG score recompute
  15. 2026-10-05 14:12 UTCGHSA enrichment
  16. 2026-10-04 23:22 UTCEPSS rescore
  17. 2026-10-04 15:38 UTCGHSA enrichment
  18. 2026-10-03 16:41 UTCEG score recompute
  19. 2026-10-03 16:41 UTCGHSA enrichment
  20. 2026-10-03 14:26 UTCEPSS rescore
  21. 2026-10-02 14:04 UTCEG score recompute
  22. 2026-10-02 14:04 UTCGHSA enrichment
  23. 2026-10-01 19:50 UTCEPSS rescore
  24. 2026-10-01 15:28 UTCEG score recompute
  25. 2026-10-01 15:28 UTCGHSA enrichment
Show 75 more
  1. 2026-10-01 06:12 UTCEG score recompute
  2. 2026-10-01 06:12 UTCGHSA enrichment
  3. 2026-09-30 07:48 UTCEG score recompute
  4. 2026-09-30 07:48 UTCGHSA enrichment
  5. 2026-09-29 15:24 UTCEPSS rescore
  6. 2026-09-28 23:24 UTCEG score recompute
  7. 2026-09-28 23:24 UTCGHSA enrichment
  8. 2026-09-28 13:52 UTCEPSS rescore
  9. 2026-09-28 00:49 UTCEG score recompute
  10. 2026-09-28 00:49 UTCGHSA enrichment
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-27 02:24 UTCEG score recompute
  13. 2026-09-27 02:24 UTCGHSA enrichment
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-26 00:28 UTCEPSS rescore
  16. 2026-09-24 21:21 UTCEG score recompute
  17. 2026-09-24 21:21 UTCGHSA enrichment
  18. 2026-09-24 14:04 UTCEPSS rescore
  19. 2026-09-24 03:01 UTCEG score recompute
  20. 2026-09-24 03:01 UTCGHSA enrichment
  21. 2026-09-23 17:54 UTCEPSS rescore
  22. 2026-09-23 04:36 UTCEG score recompute
  23. 2026-09-23 04:36 UTCGHSA enrichment
  24. 2026-09-22 16:01 UTCEPSS rescore
  25. 2026-09-22 06:11 UTCEG score recompute
  26. 2026-09-22 06:10 UTCGHSA enrichment
  27. 2026-09-21 21:09 UTCEPSS rescore
  28. 2026-09-21 07:45 UTCEG score recompute
  29. 2026-09-21 07:45 UTCGHSA enrichment
  30. 2026-09-20 20:16 UTCEPSS rescore
  31. 2026-09-20 08:54 UTCEG score recompute
  32. 2026-09-20 08:54 UTCGHSA enrichment
  33. 2026-09-19 10:09 UTCEG score recompute
  34. 2026-09-19 10:09 UTCGHSA enrichment
  35. 2026-09-18 19:28 UTCEPSS rescore
  36. 2026-09-18 11:39 UTCEG score recompute
  37. 2026-09-18 11:39 UTCGHSA enrichment
  38. 2026-09-17 13:09 UTCGHSA enrichment
  39. 2026-09-16 14:19 UTCEG score recompute
  40. 2026-09-16 14:19 UTCGHSA enrichment
  41. 2026-09-16 14:08 UTCEPSS rescore
  42. 2026-09-16 05:15 UTCEPSS rescore
  43. 2026-09-15 15:18 UTCEG score recompute
  44. 2026-09-15 15:18 UTCGHSA enrichment
  45. 2026-09-15 03:12 UTCEPSS rescore
  46. 2026-09-14 16:53 UTCGHSA enrichment
  47. 2026-09-13 18:28 UTCEG score recompute
  48. 2026-09-13 18:28 UTCGHSA enrichment
  49. 2026-09-12 20:03 UTCEG score recompute
  50. 2026-09-12 20:03 UTCGHSA enrichment
  51. 2026-09-12 15:02 UTCEPSS rescore
  52. 2026-09-11 21:38 UTCEG score recompute
  53. 2026-09-11 21:38 UTCGHSA enrichment
  54. 2026-09-11 14:53 UTCEPSS rescore
  55. 2026-09-10 23:13 UTCEG score recompute
  56. 2026-09-10 23:13 UTCGHSA enrichment
  57. 2026-09-10 09:35 UTCEPSS rescore
  58. 2026-09-10 00:42 UTCGHSA enrichment
  59. 2026-09-09 01:44 UTCEG score recompute
  60. 2026-09-09 01:44 UTCGHSA enrichment
  61. 2026-09-08 22:01 UTCEPSS rescore
  62. 2026-09-07 22:07 UTCEG score recompute
  63. 2026-09-07 22:07 UTCGHSA enrichment
  64. 2026-09-06 23:42 UTCEG score recompute
  65. 2026-09-06 23:42 UTCGHSA enrichment
  66. 2026-09-06 13:48 UTCEPSS rescore
  67. 2026-09-06 01:11 UTCEG score recompute
  68. 2026-09-06 01:10 UTCGHSA enrichment
  69. 2026-09-05 02:43 UTCEG score recompute
  70. 2026-09-05 02:43 UTCGHSA enrichment
  71. 2026-09-04 05:07 UTCEPSS rescore
  72. 2026-09-04 04:15 UTCGHSA enrichment
  73. 2026-09-03 05:46 UTCEG score recompute
  74. 2026-09-03 05:46 UTCGHSA enrichment
  75. 2026-09-02 14:12 UTCEPSS rescore

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-77220?
CVE-2026-77220 is a medium vulnerability published on August 21, 2026. PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting function that stores a pointer to a stack-local buffer in the document dictionary without copying the string value. In multi-threaded or pooled-request environments, attackers or concurrent users can…
When was CVE-2026-77220 disclosed?
CVE-2026-77220 was first published on August 21, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77220 actively exploited?
CVE-2026-77220 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77220?
CVE-2026-77220 has a CVSS base score of 6.5 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-77220?
A fix for CVE-2026-77220 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-77220 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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