Security readout for executives and security teams
Plain-English summary
CVE-2026-24688 affects pypdf, a Python PDF library. Versions before 6.6.2 can enter an infinite loop when processing a specially crafted PDF’s outlines or bookmarks. The likely business impact is resource exhaustion or stalled processing in systems that inspect PDF bookmarks. The vendor fixed it in pypdf 6.6.2.
Executive priority
Treat as a routine but timely denial-of-service fix. Prioritize internet-facing or customer-facing PDF workflows that parse bookmarks, because a crafted file could tie up processing. This is not currently evidenced as exploited in the wild and does not indicate data compromise.
Technical view
The issue is CWE-835: loop with unreachable exit condition. A crafted PDF can trigger an infinite loop in pypdf before 6.6.2 when application code accesses outlines/bookmarks. The CVE lists CVSS 4.0 score 5.1, with low availability impact and no confidentiality or integrity impact. PR #3610 and commit b1282f8 are associated with the fix.
Likely exposure
Exposure is most likely in Python applications or services using pypdf below 6.6.2 and reading PDF outlines/bookmarks from untrusted or user-supplied files. Systems that only store PDFs or do not access bookmarks may have lower practical exposure, based on the advisory description.
Exploitation context
The sources describe crafted-PDF triggering but do not cite active exploitation, public weaponization, or KEV listing. Exploitation requires the vulnerable application to process the malicious PDF and access outlines/bookmarks. The expected effect is denial of service through an infinite loop, not data theft or code execution.
Researcher notes
Key scoping condition is outline/bookmark access. The CVE record’s CVSS vector reports local attack vector despite the crafted-file scenario, so assess deployment context carefully. Sources name pypdf versions before 6.6.2 as affected and identify 6.6.2, PR #3610, and commit b1282f8 as the fix path.
Mitigation direction
- Upgrade pypdf to version 6.6.2 or later.
- If upgrade is blocked, review applying PR #3610 changes manually.
- Prioritize services processing untrusted PDFs and reading outlines or bookmarks.
- Monitor vendor advisory and release notes for any follow-up guidance.
Validation and detection
- Inventory Python applications that depend on pypdf.
- Confirm installed pypdf versions are 6.6.2 or later.
- Identify code paths that access PDF outlines or bookmarks.
- Review PDF-processing services accepting user-supplied or external files.
- Verify dependency lockfiles and deployed environments reflect the fixed version.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-835: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-24688 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.1 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-2q4j-m29v-hq73CVE reference · x_refsource_CONFIRM
- https://github.com/py-pdf/pypdf/pull/3610CVE reference · x_refsource_MISC
- https://github.com/py-pdf/pypdf/commit/b1282f8dcdc1a7b41ceab6740ffddfdf31b1fec1CVE reference · x_refsource_MISC
- https://github.com/py-pdf/pypdf/releases/tag/6.6.2CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Loop with Unreachable Exit Condition ('Infinite Loop')
Loop with Unreachable Exit Condition ('Infinite Loop') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.