{"answers":{"affected":"It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27824 exists.","fix":"Upgrade to a fixed version.","what":"CVE-2026-27824 is a medium-severity vulnerability in kovidgoyal calibre, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-27824 and fix it if it is affected.\n\nWhat it is: CVE-2026-27824 is a medium-severity vulnerability in kovidgoyal calibre, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27824 exists.\n\nAffected product: kovidgoyal calibre. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-27824/ (Markdown: https://insights.sbomify.com/CVE-2026-27824/index.md)","id":"CVE-2026-27824","markdown":"https://insights.sbomify.com/CVE-2026-27824/index.md","name":"CVE-2026-27824","record":{"aliases":["DEBIAN-CVE-2026-27824","GHSA-vhxc-r7v8-2xrw","UBUNTU-CVE-2026-27824"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"e-book manager","requires_auth":"none","summary":"Attackers can bypass IP-based brute-force protection in calibre Content Server by spoofing the X-Forwarded-For header, facilitating credential stuffing attacks.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"calibre","vendor":"calibre-ebook"}],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-346","name":"Origin Validation Error"},{"id":"CWE-307","name":"Improper Restriction of Excessive Authentication Attempts"}],"description":"calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.4.0, the calibre Content Server's brute-force protection mechanism uses a ban key derived from both `remote_addr` and the `X-Forwarded-For` header. Since the `X-Forwarded-For` header is read directly from the HTTP request without any validation or trusted-proxy configuration, an attacker can bypass IP-based bans by simply changing or adding this header, rendering the brute-force protection completely ineffective. This is particularly dangerous for calibre servers exposed to the internet, where brute-force protection is the primary defense against credential stuffing and password guessing attacks. Version 9.4.0 contains a fix for the issue.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"calibre has IP Ban Bypass via X-Forwarded-For Header Spoofing","id":"CVE-2026-27824","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"MCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachment","id":"CVE-2026-27825"},"packages":[],"prev":{"headline":"Remote Code Execution Vulnerability in EGroupware","id":"CVE-2026-27823"},"products":["calibre"],"published":"2026-02-27","related":[{"cvss_score":9.8,"headline":"Command injection in Calibre","id":"CVE-2011-4124","kev_date_added":null,"published":"2021-10-27"},{"cvss_score":9.8,"headline":"Privilege escalation in Calibre","id":"CVE-2011-4125","kev_date_added":null,"published":"2021-10-27"},{"cvss_score":9.3,"headline":"calibre: Path Traversal Vulnerability Enables Arbitrary File Write and Remote Code Execution","id":"CVE-2026-26064","kev_date_added":null,"published":"2026-02-20"},{"cvss_score":9.3,"headline":"calibre: Path Traversal can Lead to Arbitrary File Write and Potential Code Execution","id":"CVE-2026-26065","kev_date_added":null,"published":"2026-02-20"},{"cvss_score":8.6,"headline":"calibre has a Path Traversal Leading to Arbitrary File Write and Potential Code Execution","id":"CVE-2026-25635","kev_date_added":null,"published":"2026-02-06"},{"cvss_score":8.2,"headline":"calibre has a path traversal vulnerability","id":"CVE-2026-33206","kev_date_added":null,"published":"2026-03-27"},{"cvss_score":8.2,"headline":"calibre has a Path Traversal Leading to Arbitrary File Corruption and Code Execution","id":"CVE-2026-25636","kev_date_added":null,"published":"2026-02-06"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-03-02","vendors":["kovidgoyal"]},"summary":"Attackers can bypass IP-based brute-force protection in calibre Content Server by spoofing the X-Forwarded-For header, facilitating credential stuffing attacks.","url":"https://insights.sbomify.com/CVE-2026-27824/"}