Bug 2542677 (CVE-2026-101917)

Summary: CVE-2026-101917 pyjwt: PyJWT: Denial of Service via outbound request amplification on unknown key identifiers
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, alinfoot, amctagga, anpicker, anthomas, aoconnor, aos-team-art-private, aprice, asdas, bbrownin, blitton, bniver, bparees, cahl, cmyers, dfreiber, dkeler, dnakabaa, doconnor, dpaolell, dranck, drow, dschmidt, dtrifiro, eborisov, ebourniv, eglynn, ehelms, flucifre, ggainey, gmeno, groman, hasun, ilpinto, jburrell, jdelft, jfula, jjoyce, jlanda, jmitchel, jowilson, jpasqual, jpretori, jsamir, jschluet, jupierce, juwatts, jwong, kaycoth, kshier, lball, lbrazdil, lcouzens, lgarciaa, lhh, ljawale, ltomasbo, mbarnett, mbenjamin, mbiarnes, mburns, mdellweg, mgarciac, mhackett, mhayden, mhulan, mminar, msilmser, ngough, nmoumoul, nyancey, oezr, omaciel, ometelka, osousa, pcreech, ppalepu, ppostler, prdhamdh, ptisnovs, rbiba, rbobbitt, rchan, rekumar, rhel-process-autobot, rjohnson, sbunciak, sdoran, sghai, sidsharm, simaishi, smallamp, sostapov, sskracic, stcannon, suppawar, syedriko, thason, tmalecek, tpfromme, vereddy, veshanka, vkumar, vlaad, vvoronko, watson-tool-maintainers, weaton, xdharmai, yguenane, ykashtan
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in PyJWT. A remote attacker can trigger a Denial of Service (DoS) through outbound request amplification by submitting tokens containing unknown key identifiers. Because the library does not cache lookup failures or enforce a minimum refresh interval when fetching signing keys, each invalid key identifier forces a new request to the remote JSON Web Key Set (JWKS) server. This allows an attacker to exhaust network resources and overwhelm the configured authentication endpoints.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-28 20:33:17 UTC
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT get_signing_key_from_jwt is affected because unknown kid misses force refreshes without a negative cache or minimum refresh interval. This occurs when unauthenticated tokens repeatedly use the same unknown kid or varying kid values absent from the cached JWKS. As a result, each cache miss causes PyJWKClient to refresh the JWKS. Consequently, attacker traffic can amplify outbound requests to the configured JWKS endpoint. This issue is fixed in version 2.14.0.