CVE-2026-102997
published 2026-09-30CVE-2026-102997: pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data…
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.34%
26.8th percentile
pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while the earlier recovery counter fails to advance for bytes that successfully decode, causing long runtimes and application unavailability. This is a residual issue after the malformed FlateDecode recovery fix. This issue is fixed in version 6.18.1.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| ansible-automation-platform-25 | lightspeed-chatbot-rhel8 | — | — |
| ansible-automation-platform | automation-orchestrator-backend-rhel9 | — | — |
| lightspeed-core | lightspeed-stack-rhel9 | — | — |
| lightspeed-core | rag-tool-cpu-rhel9 | — | — |
| lightspeed-core | rag-tool-cuda-12.9-rhel9 | — | — |
| openshift-lightspeed-tech-preview | lightspeed-rag-tool-rhel9 | — | — |
| openshift-lightspeed | lightspeed-ocp-rag-rhel9 | — | — |
| py-pdf | pypdf | < 6.18.1 | 6.18.1 |
| pypdf_project | pypdf | < 6.18.1 | 6.18.1 |
| pypdf_project | pypdf | >= 0 < 6.18.1 | 6.18.1 |
| quay | quay-rhel8 | — | — |
| quay | quay-rhel9 | — | — |
| rhelai3 | bootc-cuda-rhel9 | — | — |
| rhelai3 | bootc-gaudi-rhel9 | — | — |
| rhelai3 | bootc-rocm-rhel9 | — | — |
| rhelai3 | disk-image-cuda-rhel9 | — | — |
| rhoai | odh-llama-stack-core-rhel9 | — | — |
| rhoai | odh-ogx-core-rhel9 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv4.08.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
vendor_redhat8.7HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Red Hat
pypdf: pypdf: Denial of Service via crafted FlateDecode stream
vendor_redhat·2026-09-30·CVSS 8.7
CVE-2026-102997 [HIGH] CWE-835 pypdf: pypdf: Denial of Service via crafted FlateDecode stream
pypdf: pypdf: Denial of Service via crafted FlateDecode stream
A flaw was found in pypdf. A remote attacker can exploit this vulnerability by providing a crafted PDF document containing a partially malformed FlateDecode data compression stream. When processing the malformed stream, the application triggers an inefficient recovery routine that consumes excessive processing time, potentially resulting in application unresponsiveness and a Denial of Service (DoS).
Package: ansible-automation-platform/automation-orchestrator-backend-rhel9 (Ansible Automation Orchestrator 2026) - Affected
Package: lightspeed-core/lightspeed-stack-rhel9 (Lightspeed Core) - Affected
Package: lightspeed-core/rag-tool-cpu-rhel9 (Lightspeed Core) - Affected
Package: lightspeed-core/rag-tool-cuda-12.9-rhel9 (Lig
GHSA
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
ghsa·2026-10-01
CVE-2026-102997 [HIGH] CWE-400 pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
### Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a partially malformed `/FlateDecode` stream, where the byte-by-byte decompression is used.
### Patches
This has been fixed in [pypdf==6.18.1](https://github.com/py-pdf/pypdf/releases/tag/6.18.1).
### Workarounds
If you cannot upgrade yet, consider applying the changes from PR [#4073](https://github.com/py-pdf/pypdf/pull/4073).
VulDB
py-pdf Pypdf up to 6.18.0 FlateDecode pypdf/filters.py resource consumption
vuldb·2026-09-30·CVSS 8.7
CVE-2026-102997 [HIGH] py-pdf Pypdf up to 6.18.0 FlateDecode pypdf/filters.py resource consumption
A vulnerability identified as problematic has been detected in py-pdf Pypdf up to 6.18.0. This issue affects some unknown processing of the file pypdf/filters.py of the component FlateDecode Handler. Performing a manipulation results in resource consumption.
This vulnerability is cataloged as CVE-2026-102997. It is possible to initiate the attack remotely. There is no exploit available.
You should upgrade the affected component.
No detection rules found.
No public exploits indexed.
2026-09-30
Published