@@ -81,6 +81,26 @@ _Exploiting these vulnerabilities requires access to the system and the ability
8181to execute code there, thus the categorization as Local Privilege Escalation (LPE),
8282not Remote Code Execution (RCE)._
8383
84+ ## Update 2026-05-13: Fragnesia
85+
86+ Yet another network fragment handling issue which fails to properly prevent
87+ in-place en/decryption which can be made to hit sensitive page cache contents
88+ that was put there with splice has been discovered with
89+ [ Fragnesia] ( https://www.openwall.com/lists/oss-security/2026/05/13/3 ) .
90+ It's a simple logic error where the sharing property is forgotten in buffer
91+ coalescing. It has gotten CVE-2026 -46300.
92+
93+ ## Update 2026-05-15: ssh-keysaign-pwn
94+
95+ This LPE is unrelated to the others; under certain circumstances, the kernel
96+ fails to prevent the dumping of process memory under ptraces, which can be used
97+ to read out sensitive data. As it can be used to read e.g. ssh keys, it has been called
98+ [ ssh-keysign-pwn] ( https://github.com/0xdeadbeefnetwork/ssh-keysign-pwn ) . It has
99+ gotten CVE-2026 -46333.
100+
101+ This vulerability allows local attackers to read sensitive data (Information
102+ Disclosure - ID) which may be useful to escalate privileges.
103+
84104## Impact
85105
86106Any system where normal (non-root) users can log in to execute code under their
@@ -124,18 +144,20 @@ The fixes for Dirty Frag are still in development as of May 8. The first fixes
124144have been merged upstream and released in 7.0.5, 6.18.28, 6.12.87, 6.6.138,
1251456.1.172, 5.15.206 and 5.10.255 but there is
126146[ more to come for rxrpc] ( https://lwn.net/ml/all/2026050859-ahead-anchovy-05e2@gregkh/ ) .
147+ Update 2026-05-11: 7.0.6 and 6.18.29 contain this last patch, older kernels don't need it.
127148The responsible disclosure process for Dirty Frag unfortunately failed due to the
128149[ patches being spotted] ( https://www.openwall.com/lists/oss-security/2026/05/07/12 ) ,
129150so the upstream maintainers and the distributors this time did not have time
130151to carefully prepare and test fixes ahead of the publication of the issue.
131152So we have to expect that it will take a few days until all Linux distributor
132- manage to ship tested fixed kernels.
153+ manage to ship tested fixed kernels. Alma Linux has done so already, others are
154+ expected to follow soon.
133155
134156A fully effective workaround is again to prevent loading the affected modules
135157by placing another file ` dirtyfrag.conf ` in ` /etc/modprobe.d/ ` :
136158
137159``` shell
138- # Temporary workaround for Dirty Frag CVE-2026-43284, CVE-2026-43500
160+ # Temporary workaround for Dirty Frag CVE-2026-43284, CVE-2026-43500, CVE-2026-46300
139161# This breaks IPsec
140162install esp4 /bin/false
141163install esp6 /bin/false
@@ -144,6 +166,16 @@ install rxrpc /bin/false
144166
145167Note that these workarounds prevent IPsec from working.
146168
169+ Update 2026-05-15: This mitigation helps against Fragnesia as well; AppArmor preventing
170+ unprivileged user namespaces (ubuntu) also helps. While a patch
171+ for Fragnesia was proposed, a fix has not been merged into the upstream kernel yet.
172+ Alma Linux has gone ahead and published a fixed kernel anyhow (for testing).
173+
174+ Update 2026-05-15: The stable kernels 7.0.8, 6.18.31, 6.12.89, 6.6.139, 5.15.207, and
175+ 5.10.256 contain a fix for the ptrace vulnerability (CVE-2026 -46333 aka ssh-keysign-pwn).
176+ The latter is hard to mitigate, as there's no Security Module hook. Setting up a seccomp
177+ that disallows ptrace would help.
178+
147179If a system is suspected to already have been exploited, the system owner can
148180dispose of the page cache by doing ` echo 3 > /proc/sys/vm/drop_caches ` as root
149181and unload the affected modules to prevent re-exploitation.
@@ -211,7 +243,7 @@ key or to use a tool like kubectl-node-shell with the appropriate
211243privileges.
212244
213245``` bash
214- for node in $( kubectl get nodes | grep -v ' ^NAME' | awk ' {print $1;}' ) do ;
246+ for node in $( kubectl get nodes | grep -v ' ^NAME' | awk ' {print $1;}' ) ; do
215247 kubectl node_shell " $node " -- bash -c ' echo -e "# Temporarily disable algif_aead (copy.fail)\ninstall algif_aead /bin/false" > /etc/modprobe.d/disable-aead-copyfail.conf'
216248 kubectl node_shell " $node " -- bash -c ' echo -e "# Temporarily disable esp4, esp6, rxrpc (Dirty Frag)\ninstall esp4 /bin/false\ninstall esp6 /bin/false\ninstall rxrpc /bin/false" > /etc/modprobe.d/disable-esp46-rxrpc-dirtyfrag.conf'
217249done
@@ -235,10 +267,40 @@ in the meantime, as advised above.
235267The SCS community infrastructure was secured on May 8 by disabling the
236268relevant modules.
237269
270+ ## Outlook
271+
272+ The density with which severe issues are currently found is notable. While the
273+ research in the referenced issues originated from human beings being suspicious
274+ that certain things were not handled correctly everywhere, they were assisted
275+ by AI tools in the search. This pattern is likely to turn up a relevant number
276+ of such issues which are reachable now using such help until we may enjoy a
277+ more quiet time again. Until a new class of weaknesses comes into the reach of
278+ yet more powerful AI tools.
279+
280+ The other notable thing is that the quiet closing of issues within the Linux
281+ Kernel no longer works which has broken the responsible disclosure process
282+ that gave defenders some headway against attackers. One reason is that
283+ once a pattern emerges, several teams compete for speed to find related issues
284+ and decide in favor of disclosing before someone else finds it also. Another
285+ reason is that there are people that now use AI tools to analyze merged bugfixes
286+ to the kernel using AI tools - the fact that they are not flagged as security
287+ issues no longer is a good cover. So software distributors need to expect more
288+ of these occurences where they are struggling to patch software, validate the
289+ fixes and ship to customers before large-scale attacks happen. Operators will
290+ need to be fast as well.
291+
292+ So yes, the times are changing in software security and open source software is
293+ hit first being the most accessible to security researchers. On the proprietary
294+ side, we can suspect similar research is happening, but whether the research
295+ teams also go for fame and visibility or maybe have other prevalent incentives
296+ is an open question.
297+
238298## Thanks
239299
240300The authors would like to thank Taeyang Lee at Xint (who initiated the
241301research on copy.fail) and Hyunwoo Kim (@v4bel , who discovered Dirty Frag).
302+ Update 2026-05-15: They would also like to acknowledge William Bowling (V12) for Fragnesia
303+ and Jann Horn and Qualys for ssh-keysign-pwn.
242304They would also like to thank the upstream Linux kernel maintainers and
243305Linux distributors for their reliable work no handling the issues and
244306getting fixes out.
@@ -254,3 +316,6 @@ SCS security contact is [security@scs.community](mailto:security@scs.community),
254316- kubectl node-shell instructions, v0.2, 2026-05-09, 12:45 CEST.
255317- Mention succssful patching of community infra, v0.3, 2026-05-09, 13:30 CEST.
256318- Correct facts on the failure of the responsible disclosure. Release as v1.0, 2026-05-09, 20:00 CEST.
319+ - Update on final rxrpc fix in stable kernels. v1.1, 2026-05-12, 08:45 CEST.
320+ - Add Fragnesia and ssh-keysign-pwn LPEs. v1.2, 2026-05-15, 17:15 CEST.
321+ - Add note on AI changing the game (outlook). v1.3, 2026-05-15, 17:30 CEST.
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