{"id":86788,"date":"2026-03-27T09:49:57","date_gmt":"2026-03-27T09:49:57","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-55197-critical-ram-exhaustion-vulnerability-in-pypdf-library","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-55197-critical-ram-exhaustion-vulnerability-in-pypdf-library\/","title":{"rendered":"<strong>CVE-2025-55197: Critical RAM Exhaustion Vulnerability in pypdf Library<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The CVE-2025-55197 vulnerability refers to a critical flaw within the pypdf library, a popular open-source pure-python PDF library. This vulnerability could allow an attacker to craft a malicious PDF, ultimately leading to RAM exhaustion. Any system or application utilizing versions of the pypdf library prior to 6.0.0 are affected, posing high risks of system compromise and data leakage.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-55197<br \/>\nSeverity: High, CVSS score 7.5<br \/>\nAttack Vector: Malicious PDF file<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: Required (needs to open or read the malicious PDF)<br \/>\nImpact: Potential system compromise and data leakage due to RAM exhaustion<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1970718948\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p>pypdf | Prior to version 6.0.0<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability resides in the handling of PDF files with a series of FlateDecode filters used on a malicious cross-reference stream. When the affected version of pypdf reads such a file, it can lead to RAM exhaustion, potentially causing system instability or crash. Other content streams are also affected when accessed explicitly.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-2064699939\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>Here is a pseudo-code example of how a malicious PDF might be crafted. This should not be used for malicious purposes.<\/p>\n<pre><code class=\"\" data-line=\"\"># Creating a PDF with a series of FlateDecode filters\n# (This is a conceptual example, not actual usable code.)\npdf = PDF()\nxref_stream = XrefStream()\n# Adding a series of FlateDecode filters\nfor i in range(1000000):\nxref_stream.add_filter(&#039;FlateDecode&#039;)\n# Adding the malicious xref stream to the PDF\npdf.add_xref_stream(xref_stream)\n# Saving the malicious PDF\npdf.save(&#039;malicious.pdf&#039;)<\/code><\/pre>\n<p>Please note that this is a simplified pseudo-code to provide a basic understanding of the vulnerability. In real-world scenarios, the PDF would likely contain more complex structures and data.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The CVE-2025-55197 vulnerability refers to a critical flaw within the pypdf library, a popular open-source pure-python PDF library. This vulnerability could allow an attacker to craft a malicious PDF, ultimately leading to RAM exhaustion. Any system or application utilizing versions of the pypdf library prior to 6.0.0 are affected, posing high risks of system [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-86788","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86788","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=86788"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86788\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86788"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86788"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86788"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86788"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86788"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86788"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86788"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86788"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86788"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}