7.1

CVE-2026-77220: michaelrsweet pdfio Expired Pointer Dereference

CVSS: 7.1v4.0HighDeferred
AliasesUBUNTU-CVE-2026-77220DEBIAN-CVE-2026-77220
Published 21-08-2026Last modified 01-10-2026
Open JSON

Vulnerability summary

CVE-2026-77220 is a high (CVSS 7.1) Expired Pointer Dereference vulnerability in michaelrsweet pdfio. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35.3% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v4.0 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.18 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 21-08-2026
    PublishedVulnerability first disclosed.
  2. 01-10-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.18 pp

From 0.24% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian2 products
  • ippsampleAll versions (No fix recorded)
  • pdfio< 1.6.5+dfsg-1
Michaelrsweet1 product
Ubuntu1 product
  • ippsampleAll versions (No fix recorded)

3 vendors · 4 products

References

6 links