CVE WatchOct 14, 2026

CVE-2020-8492

Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct

CVSS

6.5

Medium

EPSS

6.6%

p94

KEV

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Exploit Today

0-100

Published: Jan 30, 2020 · Last modified: Oct 14, 2026 · CWE-400

EPSS · 30d

6.6%EPSS · 30 days6.6%

2026-10-142026-11-11

Technical description

Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-685407.5 HIG

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——0fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.6.0 to before version 0.33.0, quadratic style-list reprocessing during containing-block resolution for absolutely-positioned pseudo-elements cause denial of service. This issue has been patched in version 0.33.0.17h CVE-2026-685397.5 HIG

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——0fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.4.4 to before version 0.29.0, the CSS string-set named-string values resolved from a document were accumulated per element with no memory budget, letting a small crafted document amplify into large retained memory (and the CPU to copy it) — results in a denial of service. This issue has been patched in version 0.29.0.17h CVE-2026-685387.5 HIG

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——0fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.15.0 to before version 0.27.0, resolving the CSS counters(name, sep) function in generated content was bounded neither in the size of a single expansion nor in the aggregate work across an element tree. An attacker able to submit HTML/CSS to a fulgur-based conversion service can trigger CPU and memory exhaustion with a trivially small payload, denying service to the host and any co-tenants. This issue has been patched in version 0.27.0.17h CVE-2026-1261617.5 HIG

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——0A uncontrolled resource consumption vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.6 may allow a remote unauthenticated attacker to cause a denial of service via repeated unauthenticated POST requests.17h CVE-2026-1238685.9 MED

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——0An unauthenticated HTTP/2 client can exhaust Node.js server memory because inbound DATA queued on an undrained stream is charged to no session budget. Each inbound DATA frame creates one JavaScript Buffer view in the receiving stream's readable queue, but nothing charges that queue to current_session_memory_: the socket read buffer is accounted only during parsing and released immediately, so whatever stays queued is accounted to nothing. A peer that fills a stream's receive window with one-byte DATA frames pays about 10 wire bytes per frame while the server retains about 114 bytes per frame, so a single stream on one connection can retain hundreds of megabytes from tens of megabytes sent. maxSessionMemory neither bounds the growth nor refuses new streams, because Http2Session::CanAddStream gates admission on the same counter that never sees the queue. This vulnerability affects Node.js 26.x and 24.x.20h CVE-2026-1238657.5 HIG

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——0An unauthenticated HTTP/2 client can permanently leak Node.js server memory and file descriptors. If a peer triggers a protocol error, for example an oversized frame header, while the session is already shutting down, nghttp2 tears the session down internally but Node.js never notices, leaving a dangling session: the socket stays in CLOSE_WAIT and all of Node.js's HTTP/2 state for that connection is held in memory indefinitely, with no further cost to the attacker. The attacker can start the shutdown remotely by sending GOAWAY(NO_ERROR), so it is reliable against default HTTP/2 servers. It is an incomplete-fix case of CVE-2026-48937: that fix detected nghttp2 internal terminations by watching for GOAWAY sent while not shutting down, but missed terminations that arrive while the session is already shutting down. This vulnerability affects Node.js 26.x, 24.x, and 22.x.20h