Every CVE Search/ Get API key

CVE-2026-77220

PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting

7.1 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
High
Availability
None

Exploit likelihood

0.42%Up 0.2 points since Aug 22, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.1

PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting

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.

Record
CVE-2026-77220
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-825
Updated
2026-11-02
EUVDEUVD-2026-64163 7.1

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.

Record
EUVD-2026-64163
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-2fr4-jfvm-chmp 7.1

PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting...

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.

Record
GHSA-2fr4-jfvm-chmp
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-825
Updated
2026-11-02
NVD 7.1

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.

Record
CVE-2026-77220
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-825
Updated
2026-11-02
OSV 7.1

PDFio < 1.6.5 Dangling Pointer via Dictionary String-Formatting

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.

Record
CVE-2026-77220
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness
CWE-825
Updated
2026-11-02
OSVDEBIAN-CVE-2026-77220 7.1

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.

Record
DEBIAN-CVE-2026-77220
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated
2026-11-02
OSVUBUNTU-CVE-2026-77220 7.1

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.

Record
UBUNTU-CVE-2026-77220
CVSS 4.0
7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
ippsample
Debian:12
All versions, plus listed versions
0.0.0~git20220215.f365352-10.0.0~git20220215.f365352-20.0~git20220607.72f89b3-1
None known
ippsample
Debian:14
All versions, plus listed versions
0.0.0~git20220215.f365352-10.0.0~git20220215.f365352-20.0~git20210916.53e4740-10.0~git20210916.53e4740-20.0~git20211022.c75af30-10.0~git20211022.c75af30-20.0~git20220215.f365352-10.0~git20220607.72f89b3-1
None known
pdfio
Debian:14
before 1.6.5+dfsg-1, plus listed versions
1.5.1+dfsg-11.6.1+dfsg-11.6.1+dfsg-21.6.1+dfsg-31.6.2+dfsg-11.6.3+dfsg-11.6.3+dfsg-2
1.6.5+dfsg-1
ippsample
Ubuntu:18.04:LTS
All versions, plus listed versions
0.0+20180213-0ubuntu1
None known
ippsample
Ubuntu:20.04:LTS
All versions, plus listed versions
0.0+20180213-0ubuntu1
None known
ippsample
Ubuntu:22.04:LTS
All versions, plus listed versions
0.0+20180213-0ubuntu1
None known
ippsample
Ubuntu:24.04:LTS
All versions, plus listed versions
0.0+20180213-0ubuntu10.0+20180213-0ubuntu20.0+20180213-0ubuntu3
None known
ippsample
Ubuntu:26.10
All versions, plus listed versions
0.0.0~git20220215.f365352-1build10.0.0~git20220215.f365352-2
None known
ippsample
Ubuntu:26.04:LTS
All versions, plus listed versions
0.0+20180213-0ubuntu30.0.0~git20220215.f365352-10.0.0~git20220215.f365352-1build1
None known

History

History
RecordedChangedSources
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-77220 is a high vulnerability (CVSS 7.1) in Michaelrsweet Pdfio, published August 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. Fixed in pdfio 1.6.5+dfsg-1.

References

Show 4 moreShow less
MoveEnter Open